A number of techniques are known that enable selected strands of hair to be treated and masked from unselected hair. For example, European Patent no. 0,122, 145 discloses a hairdresser's masking sheet comprising a substrate of flexible material having an adhesive strip carried by the substrate for effecting attachment of the sheet to selected strands of a head of hair prior to treatment and for rapid removal of the strands from the substrate after treatment. The masking sheet comprises two rectangular panels, of substantially the same dimensions, which are welded together along a common edge to form a transversely extending hinge about which the panels are pivotable relative to one another. The hinged joint enables the panels to be hinged apart to receive the selected strands of hair between the panels and brought into proximity with each other to envelop the selected strands so that the strands may undergo a treatment process within the envelope so formed.

In one known example the masking sheet comprises a first panel of opaque flexible sheet material, for example polyester, and a second panel of substantially transparent flexible sheet material welded to the first along a common edge. The transparent panel allows the hairdresser to monitor the progress of the colouring/bleaching

process.

There are a number of drawbacks and disadvantages associated with hairdresser's masking sheets of the type described in EP 0,122, 145. For example, the adhesive securing means (strip) becomes ineffective when brought into contact with many of the substances used to treat the selected hair. Consequently, the device tends to be labile, often slipping from the selected hair, thus requiring repositioning or replacement. Furthermore, the strips of adhesive material provide a barrier to treatment substances. Therefore, it is difficult to treat all of the selected hair within the envelope, particularly the roots of the selected strands that remain outside the envelope on the other side of the adhesive strip in use. Additionally, a problem experienced by hairdressers includes excessive application of treatment substances.

For example, the application of too much treatment substance to the hair or to the interior of the envelope can lead to over processing of the selected strands, wastage of treatment substances and leakage of excess treatment solution from the envelope. The latter can be particularly problematic if excess treatment solution drips onto the clothing of the person undergoing the treatment process and causes bleaching or discolouration thereof. If too much treatment solution is applied and over processing occurs, the selected strands tend to tangle with neighboring strands when the treatment solution is washed out and the hair is dried. This can lead to some of the selected strands breaking when subsequently combed. This problem arises from the fact that the hair cuticles become raised during over processing and the raised cuticles then interlock with the cuticles neighboring strands, which causes tangling of the hair when it is dried.

According to an aspect of the invention there is provided a hairdresser's masking aid for masking selected strands of a head of hair from other strands of hair while the selected strands are treated, the masking aid comprising at least two panels of flexible sheet material which are capable of being hinged apart to receive the selected strands of hair between the panels and subsequently brought into proximity with each other to envelop the selected strands in use, characterized in that the masking aid further comprises a bag like reservoir pouch for containing treatment process substances or \ precursors to treatment substances.

The pouch is preferably provided in a region of the masking aid remote from the end of the masking aid in proximity to the scalp in use. In preferred embodiments the pouch is provided in a region of the masking aid furthest from the end'of the masking aid in proximity to the scalp.

Preferably, the panels are hinged together along a respective edge of the masking aid and the pouch is provided adjacent to the hinge between the panels.

Adjacent panels may be partially sealed together to provide a partially sealed pouch between them or each pair of adjacent panels. Preferably, one side of the pouch is open for receiving excess treatment solution applied to the selected strands in use.

In preferred embodiments of this aspect of the invention a window of substantially transparent material is provided in the pouch. The window enables the hairdresser to observe the level of excess produce in the reservoir in use, even if working in a

different area of the hairdresser's salon or on a different head of hair. This can alert the hairdresser to prevent leakage from the reservoir if the reservoir is close to overfilling.

The reservoir may provide a receptacle for treatment substance, preferably liquid treatment substance. The reservoir may act to receive excess treatment substance, or to house treatment substance, or precursors thereto, prior to treatment taking place.

The reservoir may be provided with an absorbent substance, a porous substance or a treatment neutraliser, which may be used to mop up, store or neutralise treatment substance.

The reservoir is preferably formed in an area of the sheet remote from the scalp, i. e. in spaced relation to the scalp, preferably a portion of the sheet disposed furthest away from the scalp when in use. The reservoir is preferably formed adjacent the pivotable portion (hinge), which joins the portions of the sheet. The reservoir may comprise a trough, blister or bubble type pouch formed in or by one or more parts (panels) of the sheet. In a particularly preferred embodiment, the reservoir comprises a trough, blister or bubble formed adjacent the hinge between the two panels.

Preferably, the reservoir is formed from flexible, optionally resilient material.

Resilient material allows the reservoir to retain its volume after, for example, being squeezed.

In a further particularly preferred embodiment, the two panels are partially sealed

together to form a flap or tab with the reservoir formed therein, and means are provided to enable liquid to flow into the reservoir from the unitable envelope or vise versa.

One or more channels may be formed in the sheet material, or in a selected portion thereof, which directs liquid into or out of the reservoir. Similarly, a channel or channels may be formed in the sheet, which allows distribution of liquid throughout an area of the sheet.

The reservoir may be sealed prior to use. In this embodiment, the reservoir may contain a treatment substance or precursor thereto. For instance, a frangible seal may be provided which is broken to allow treatment substance to enter the, envelope and treat the hair. Alternatively, or in addition, the reservoir may be used to replenish the treatment substance in the envelope. For example, as treatment substance drains into the reservoir and collects, a squeeze of the reservoir allows treatment substance to be reapplied to the selected hair within the envelope as it is pushed out of the reservoir into the envelope. If, after sometime, it becomes clear to the hairdresser, when observing the progress of the treatment through the window or transparent front sheet, that the produce has been applied unevenly, and parts ofthe selected strands have been missed and are not changing colour with the rest of the strands, it is possible to manipulate the excess produce, using thumb and forefinger, from the reservoir to those areas where the produce was not applied during the original application.

The reservoir may be used to house treatment substance precursors. For example, the

reservoir may contain a colorant precursor or a bleach precursor. During use, the hairdresser applies a first precursor to the selected hair and unites the panels to envelop the hair. The reservoir may then be opened, for example by breaking a frangible seal, and a second precursor is expelled therefrom, into contact with the precursor on the hair. A reaction between the precursors then takes place resulting in treatment of the selected hair. This is particularly advantageous as it provides a relatively clean treatment process. For example, handling of messy or hazardous treatment substances prior to application to the hair is avoided.

The reservoir preferably has a volume of 0. 1-5ml, more preferably 0. 25-3ml, most preferably about 2ml.

In embodiments of the present invention, the sheet is preferably constructed in whole or part from a flexible polymeric material, for example a polyolefin. Alternatively, a portion of the sheet or all of the sheet may be constructed from a metal foil material.

Preferably, at least some area of the sheet is opaque, preferably a light coloured material, preferably a substantially white material. In one embodiment of the present invention, an opaque sheet comprises a window of transparent material through which the selected strands of hair may be viewed. In other preferred embodiments the masking aid comprises a metal foil sheet material laminated with a thin film of transparent polyester or like material.

The sheet material is preferably rectangular, most preferably elongate rectangular material. In some embodiments, for example, where a reservoir is present, extensions

to the sheet material of a non-rectangular shape may be provided.

The two panels of the sheet are preferably of substantially equal area. It is particularly preferred that when the two panels are united, one panel may be substantially superimposed on the other. The panels maybe formed from a single sheet of material provided with a pivotable portion enabling the two panels to unite or approximate to form an envelope. The pivotable portion may be a hinge, for example, a hinge created by plastically deforming the sheet material to form the hinge. Alternatively, the masking sheet may be formed from two separate panels, which are attached to one another, for example welded or heat sealed together, to form the pivotable portion.

Preferably, the pivotable portion is a transversly extending hinge.

According to a second aspect of the invention there is provided a hairdresser's masking aid for masking selected strands of a head of hair from other strands of hair while the selected strands are treated, the masking aid comprising at least two panels of flexible sheet material which are capable of being hinged apart to receive the selected strands of hair between the panels and subsequently brought into proximity with each other to envelop the selected strands in use, characterized in that the masking aid further comprises securing means adjacent an edge of the masking aid having liquid conducting channels formed adjacent thereto, said channels adapted to facilitate liquid flow past the securing means towards the edge of the sheet.

The present invention provides numerous advantages over the prior art. For example, the liquid conducting channels enable a greater percentage of selected hair to be

treated, in particular, hair located close to the edge of the masking aid, for example portions of the hair adjacent the scalp.

In preformed embodiments, the liquid conducting channels facilitate liquid flow towards the roots of the strands by capillary action along with the enclosed strands of hair. The securing means may permit accurate location of the masking substrate relative to selected strands of hair so that the substrate abuts the scalp of a head of hair. This is particularly advantageous if bleaching or coloration of selected strands is required, thereby ensuring that the whole of the strands outwardly from the scalp are treated. The securing means may also permit accurate location of the substrate in a longitudinal direction of selected strands in spaced relation to the scalp, so that only selected, for example, lower portions of the selected strands between the scalp and the substrate may be treated.

The securing means may be mechanical engaging means., In a particularly preferred . embodiment, the securing means comprise an adhesive, substance, preferably a pressure sensitive adhesive. Such adhesive may be adapted to adhere to hair and/or adjacent sheet material. Where the securing means are adhesive, a continuous or discontinuous adhesive layer may be applied to a portion of one or more of the panels.

The adhesive maybe in the form of a strip of adhesive or discrete islands of adhesive.

The adhesive may be recessed in the surface of the sheet, or embossed thereon.

Preferably, securing means are located on one or both of the panels, which unite to form the envelope. In addition, securing means may be provided on the outer face of

the sheet, i. e. the outer surface of the envelope in use. In this embodiment, the securing means may be used to secure the sheet to hair strands external of the envelope, and/or to adjacent sheet material.

In a particularly preferred embodiment, the securing means are discontinuous. For example, when adhesive is formed on the internal surface of the envelope, it is particularly advantageous to provide channels adjacent to portions of the adhesive, which allow treatment substances to pass between the portions of adhesive. This enables a greater area of selected hair to be treated. Furthermore, it provides a mechanism whereby treatment substances can migrate towards the edge of the sheet, thereby contacting portions of the hair adjacent to the scalp. In this embodiment, the panels may be adapted to provide a space between the panels, which facilitates movement, by capillary action, of treatment solution. Such a space may be provided by spacing means, for example, protrusions on the surface of the panel, or for example, the securing means, such as an adhesive strip, may provide the spacing means. The surface of the panels in the channel regions may be treated or coated to facilitate capillary action.

In an alternative embodiment, a flap or strap of material may be provided which folds across selected strands of hair and is attached to a portion of one of the panels, thereby trapping hair between itself and a portion of the panel. In this way, strands of hair maybe placed on the panel and the flap or strap folded across them to secure the sheet to the hair. The treatment may then be applied and the envelope closed. The flap or strap may itself comprise securing means, such as adhesive, for securing the flap or

strap to the hair and/or a respective panel.

According to a third aspect of the invention there is provided a hairdresser's masking aid for masking selected strands of a head of hair from other strands of hair while the selected strands are treated, the masking aid comprising at least two panels of flexible sheet material which are capable of being hinged apart to receive the selected strands of hair between the panels and subsequently brought into proximity with each other to envelop the selected strands in use, characterized in that a first panel of the masking aid comprises an enclosed or partially enclosed securing means, the first panel having apertures formed therein permitting the securing means to contact strands of hair, thereby securing the sheet to the hair.

In a particularly preferred embodiment of the present invention, a flap is provided, preferably extending from a portion of a panel adjacent the scalp in use. The flap is preferably pivotly attached to a panel of the masking and sheet. Preferably, the flap may be folded back. into engagement with a corresponding portion of the panel and/or into engagement with a material disposed between the panel and the flap.

Alternatively, a portion of the panels may comprise a two-ply laminate structure, between which a securing means may be located. These arrangements preferably provide an enclosure or partial enclosure within which a securing means may be secured. Preferably, the flap and/or the portion of panel adjacent the flap is provided with apertures, through which the securing means may engage selected strands of hair.

Preferably, the apertures extend through the pivotable portion, through which the flap is attached, to the panel. Thus, a comb-like structure may be provided, the panel and

the flap bearing the teeth of the comb and the apertures providing the gaps between the teeth. A securing means may be sandwiched between the flap and the panel and may be visible in the gaps between the teeth of the comb-like arrangement.

In a particularly preferred embodiment, the enclosed securing means may be formed by folding a margin of the sheet back on itself to form a second envelope (with respect to the first envelope, hereinafter referred to, formed by approximation of the two panels of the masking) and sandwiching the securing means therebetween. In these embodiments, the securing means may be adapted to contact hair strands both inside and outside the first envelope in use, but as the securing means are preferably slightly recessed in the apertures, do not engage adjacent sheets thus facilitating stacking or packaging of sheets without securing one to another.

In a particularly preferred embodiment, the securing means may be contacted by selected hair strands from within the envelope, through the apertures, and may be contacted by hair or adjacent sheets from outside the envelope. This provides a plurality of secure contacts, increasing the stability of the device.

According to a fourth aspect of the invention there is provided a hairdresser's masking sheet for masking selected strands of hair from other strands of hair while selected strands are treated, the sheet comprising two portions which are pivotable relative to one another such that one portion may be brought into proximity with the other portion so as to envelop the selected strands, characterised in that a portion of the sheet is provided with teeth and adapted to receive strands of hair in the spaces

between teeth.

Another problem encountered by hair colourists and the like occurs when masking sheets of substantial opaque material, for example metal foil, are used to mask the selected strands of hair. Such opaque sheets do not readily enable the hair colourist to monitor the colouring or bleaching process without opening the envelope formed by the masking sheet around the selected strands of hair. This is an important consideration because as the hair grows out of the scalp it receives oxygen from the atmosphere and a hardening process known as keratinisation occurs. Keratinisation, or full keratinisation, takes about 6 weeks for normal hair, which is equivalent to about 25mm (1 inch) growth. The first 25mm of hair from the root is not, therefore, fully keratinised and more readily absorbs the active chemicals of the hair treatment substance used for colouring or bleaching. The remaining length of hair is fully keratinised and is hard and horn-like in texture. The greater hardness. of the keratinised hair makes it much harder for the chemicals to penetrate the hair and this increases the amount of time required for the chemicals to be absorbed, which increases the process time. This is not necessarily a problem when highlighting selected strands by bleaching since the desired effect is to remove all pigment from root to tip and similarly where a whole head of hair is to be coloured darker than the hair's natural colour. However, the difference in processing times is significant when a whole head of hair is to be coloured lighter than the hair's natural colour and currently it is necessary for the hair colourist to first apply the treatment substance to the middle lengths and ends of the hair and wait for a predetermined amount of time, for example 20 minutes, before the same substance is applied to the roots in order to

achieve even colouring. When using opaque masking sheets, such as metal foil, it is therefore, necessary for the hair colourist to periodically check that the roots have been processed sufficiently so that they are the same colour as the remaining keratinised part of the hair. As previously mentioned this involves the colourist periodically opening the envelope formed by the metal foil to observe the extent of the colouring process..

There is a requirement, therefore, for an improved masking aid which readily enables hair technicians to monitor the colouration of hair being treated in the region of the non keratinised (or not fully keratinised) hair at the root adjacent to the scalp without having to remove, or at least open, the metal foil, or other opaque material, comprising the masking sheets.

According to a fifth aspect of the present invention there is provided a hairdresser's masking aid for masking selected strands of a head of hair from other strands of hair while the selected strands are treated, the masking aid comprising at least two panels of flexible sheet material which may be hinged apart to receive the selected strands of hair between the panels and brought into proximity with each other to envelop the selected strands in use, characterised in that an edge portion of a substantially opaque front panel has at least one window for observing the root portions of the selected strands being treated within the envelope adjacent to the scalp.

In preferred embodiments, the front panel is also provided with a second window spaced from the edge portion for observing non-root portions of the selected strands

within the envelope.

The two-window arrangement (top edge window and second window), in this embodiment of the invention has the advantage that the hair colourist can easily monitor the different stages of activation of the treatment substance on the non- keratinised roots and the keratinised middle and end parts of the hair. The windows enable the hair colourist to monitor this process from a distance, for example, while working elsewhere in the colourist's salon, for instance on another person's hair, without having to stop, go over to the person who's hair is being treated and open the foil or other opaque masking sheet to see how the reaction process is progressing, as is currently the case. By separating the windows in this two-window arrangement it is possible for the hair colourist to compare the colours of the non-keratinised root with the keratinised middle lengths and ends because the intermediate hair, where it starts to keratinise, is covered by the opaque region of the sheet between the windows, thereby making comparison of the two parts of hair relatively easy.

Another drawback associated with the masking sheet described in EP 0,122, 145 is that the upper edge portion of the transparent front panel, that is the edge of the front panel that is in contact with the adhesive strip before the panels are separated and hinged apart, tends to curl up, around and upon itself and away from the plane of the panel when it is released from the adhesive when the masking sheet is opened in readiness for use. The edge portion of the panel curls because the surface in contact with the adhesive stretches when it is separated from the adhesive. The curled edge is a problem because it does not naturally uncurl, or unfold, back to its original flat state

when the front and rear panels are brought back together again to close the envelope along the edge. This enables treatment solution to leak from the envelope along the unclosed curled edge leading to bleaching or colouration ofunselected strands of hair that are outside the envelope, particularly those strands of hair that lie on top of the envelope during treatment. This is a particular problem when highlights are added to a head of hair since discolouration of unselected strands of hair can easily occur. It will be understood to those skilled in the art that when the panels are brought together they are held together substantially by cohesion due to the surface tension of the treatment solution. However, these forces are insufficient to flatten and straighten the curled edge, and therefore any treatment solution that falls on the curled edge portion of the front panel when the envelop is open, principally during the application of the solution, will not be contained within the envelope when the panels are brought together to close the envelope. This problem can occur even if the end portions of the adhesive strip are re-attached to the respective parts of the edge portion of the front panel when the envelope is closed.

The curled edge can also make the masking sheet more difficult to handle, particularly when the sheet is held in one hand while the hairdresser applies treatment solution to the selected strands with their other hand. It will be readily appreciated therefore that the hairdresser must take considerable care when using masking sheets of the aforementioned type to avoid treatment solution falling on the edge portion of the front panel during the application of the solution to the selected strands of hair.

There is also a requirement therefore for an improved hairdresser's masking aid of the

aforementioned type which reduces, at least partially, the probability of treatment solution coming into contact with selected strands of hair, particularly those strands that lie on top of the selected strands that are enclosed, in use, between the front and rear panels of the masking sheet.

According to a sixth aspect of the invention there is provided a hairdresser's masking aid for masking selected strands of a head of hair from other strands of hair while the selected strands are treated, the masking aid comprising at least two panels of flexible sheet material which may be hinged apart to receive the selected strands of hair between the panels and brought into proximity with each other to envelop the selected strands in use, one of the panels having an adhesive contact surface or surfaces for removably attaching the masking aid to selected hair, characterised in that an edge portion of at least one other panel has a stiffness greater than the remaining part of that panel.

In this aspect of the invention the stiffness of the edge portion is sufficient to substantially prevent distortion of the edge portion, in particular curling, due to stretching when the edge portion is separated from the adhesive in readiness for use. In this way it is possible to prevent, or substantially reduce, leakage of the treatment solution from the upper edge portion of the masking aid/sheet in use.

In preferred embodiments of the invention the edge portion comprises a plurality of layers. of the said flexible material. Preferably, but not necessarily, the stiffer edge portion comprises a portion of the flexible material folded over on itself to provide at

least one additional layer. Preferably, only one additional layer is provided, that is to say, the edge portion has twice the thickness and therefore twice the stiffness as the remaining part of the panel. The present inventor has found that this doubling of the thickness is sufficient to prevent distortion of the edge portion of the panel when the edge is separated from the adhesive on or associated with the adjacent panel.

Preferably, the panels are joined together along a common edge of the respective panels. For example, the panels may be joined by welding, by the application of heat and/or pressure, by ultrasonic welding, or by adhesive along a common edge thereof.

In embodiments where only two panels are joined together they may be co-extruded, alternatively the panels may be adjacent portions of the same sheet folded over each other.

The stiffer edge portion is located along an edge of the panel opposite the hinged edge of the panels that is to say opposite the common edge of the masking aid/sheet where the panels are j oined together. In this way the adhesive is provided along an edge of a first of the panels opposite the hinged edge and the stiffer edge portion of a second adjacent panel overlies the adhesive on the first panel when the panels are brought together. The adhesive may be provided as a single strip or in discrete pockets spaced apart along the edge of the first panel opposite the hinged edge thereof. When the adhesive is provided in discrete pockets the gaps between the adhesive pockets advantageously allow treatment solution to pass over the adhesive towards the roots of the hair being treated to ensure the selected strands of hair are treated effectively from root to tip.

In one preferred embodiment the masking aid of the aforementioned aspect of the present invention comprises a pair of hinged panels, that is to say the masking aid can be opened to form of a single substantially planar sheet. In another preferred embodiment the masking aid comprises a plurality of hinged panels, including at least one further panel overlying the said second panel. This arrangement advantageously enables different strands of hair to be selected and positioned between different sheets so that different treatment solutions can be applied to different selected strands of hair substantially without cross-contamination of the treatment solutions. For example, a first strand of hair may be selected by the hairdresser and placed between a first and a second of the panels for treatment with a first dye and a second strand, adjacent to the first strand, may be placed between the second and a third panel for treatment with a different colour dye.

The panels are substantially the same shape and size so that they overlie one another when they are brought together. Advantageously, the panels are substantially rectangular. in shape.

Another drawback associated with known masking sheets of the aforementioned type is that the sheets only permit one chemical treatment to be applied to the selected strands of hair engaged by the sheet. The masking sheets do not readily enable hairdressers to apply different dyes to adjacent strands of hair, for example the application of one colour to one strand and another colour to an adjacent strand, without using multiple sheets in close proximity to each other.

There is a requirement therefore for an improved masking aid/sheet of the aforementioned know type, which readily enables different treatments to be applied to adjacent strands of hair.

According to seventh aspect of the invention there is provided a hairdresser's masking aid for masking selected strands of a head of hair from other strands of hair while the selected strands are treated, the masking aid comprising a first panel and at least two further panels of flexible sheet material that are hinged to the first panel in an overlying relationship with the first panel so that the panels may be hinged apart to receive selected strands of hair between the panels and brought into proximity with each other to envelop the selected strands in use, the said first panel having an adhesive contact surface or surfaces for removably attaching the panel to selected hair.

The masking aid according to this aspect of the invention has at least two panels, which over lie another panel allowing different treatment solutions for different treatment processes to be applied to adjacent strands of hair. This arrangement advantageously enables different strands of hair to be selected and positioned between different panels so that different treatments solutions can be applied to the different selected strands of hair substantially without cross-contamination of the treatment solutions In a preferred embodiment, two further panels overlie the first panel so that a first strand. of hair may be selected by the hairdresser and placed between a first and a second of the panels for treatment with a first dye and a second strand, adjacent to the

first strand, may be placed between the second and a third panel for treatment with a different colour dye. The present invention also contemplates embodiments where more than two additional panels are provided which overlie each other so that more than two different treatment solutions can be applied to different strands of hair in close proximity with one another.

Preferably, the panels are substantially the same shape and size so that the panels form a stack of panels joined together along a common edge.

In one embodiment, two or more additional panels may be are arranged side by side overlying one or more larger size panels.

In preferred embodiments, the first panel may have an adhesive contact surface or surfaces for removably attaching the panel to the selected hair to be treated, and an edge portion of at least one of the further panels has a stiffness greater than the remaining part of that panel.

Preferably, a first of the panels is substantially opaque and the additional panels are substantially transparent or have at least one substantially transparent window therein so that progress of the treatment process can be monitored by the hairdresser in use.

Various embodiments of the present invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a plan view of one embodiment of a masking sheet substrate comprising a reservoir, in accordance with an embodiment the present invention; Figure 2 shows a cross-section of a partially assembled masking sheet substrate as shown in Figure 1, (the reservoir section is assembled but the hair contacting portions are only partially approximated); Figure 3 shows a perspective view of the masking sheet substrate shown in Figure2; Figure 4 shows a plan view of one embodiment of a masking sheet substrate comprising a reservoir; Figure 4 a shows a plan view of one embodiment of a masking sheet substrate comprising a reservoir ; Figure 5 is a cross-section view of a partially assembled masking sheet substrate derived from that shown in Figure 4; Figure 6 is a perspective view of the partially assembled masking sheet substrate shown in Figure 5; Figure 7 is a perspective view of a partially assembled masking sheet substrate having a reservoir bearing a treatment substance; Figure 8 is a plan view of a masking sheet substrate having spaced adhesive strips; Figure 9 is a cross-section view of the masking sheet substrate shown in Figure 8, assembled into an envelope; Figure 10 is a masking sheet substrate bearing spaced adhesive islands and adhesive strips; Figure 11 shows a side view of the masking sheet substrate shown in Figure

10, united to form an envelope; Figure 12 is a plan view of a masking sheet substrate bearing spaced adhesive strips and a transparent window; Figure 13 is a perspective view of the masking sheet substrate shown in Figure 12, pivoted at a hinge; Figure 14 is a plan view of a masking sheet substrate comprising an apertured flap, which encloses an adhesive strip; Figure 15 is a side view of the masking sheet substrate shown in Figure 14, with portions united to form an envelope; Figure 16 is a plan view of the masking sheet substrate shown in Figure 14, prior to enclosure of the adhesive strip, (the adhesive strip is absent); Figure 17 is a perspective view of a partially pivoted masking-sheet substrate as shown in Figure 16; Figure 18 is a plan view of a masking sheet substrate as shown in Figure 16, with the adhesive strip in place, prior to enclosure of the adhesive strip; Figure 19 is a perspective view of a partially pivoted masking sheet substrate as shown in Figure 14; Figure 20 is a perspective view showing how selected hair strands lie on the masking sheet substrate of Figure 19, prior to closure of the envelope; Figure 21 is a perspective view of a partially pivoted envelope bearing an adhesive strip on the inside and outside of the envelope; Figure 22 is a plan view of a masking sheet substrate bearing an adhesive strip and having teeth along one edge of the substrate ; Figure 23 is a side view of the masking sheet substrate shown in Figure 22;

Figure 24 is a plan view of a masking sheet substrate having a securable strap; Figure 25 is a plan view of a masking sheet substrate having a securable strap; Figure 26 is a perspective view of the masking sheet substrate shown in Figure 25; Figure 27 is a plan view of a masking sheet substrate according to another embodiment of the present invention; Figure 28 is a perspective view of the masking sheet of Figure 27; Figure 29 is a detailed plan view of an unfolded top edge portion of a rear panel of the masking sheet substrate shown in Figures 27 and 28; Figure 30 is a plan view of a web of masking sheets according to an embodiment of the invention; Figure 31 is a perspective view of a roll of a web masking sheets as shown in Figure 30 ; Figure 32 shows the roll of masking sheets of Figure 31 arranged within a dispensing container; Figure 33 is a plan view of one side of a masking sheet according to an embodiment of the invention; Figure 34 is a plan view of the reverse side of the masking sheet shown in Figure 33; Figure 35 is a perspective view of the masking sheet shown in Figures 33 and 34 when folded to form an envelope in readiness for use; Figure 36 is a plan view of a masking sheet front panel for a masking sheet according to an embodiment of the invention; Figure 37a is a plan view of the front panel of Figure 36 having its top edge

folded over on its self; Figure 3 7b is a plan view of the reverse side of the folded front panel shown in Figure 37a ; Figure 38 is a plan view of a masking sheet rear panel for a masking sheet according to an embodiment of the invention; Figure 39 is a plan view of a hairdresser's masking sheet, according to an embodiment of one aspect of the invention, with the panels of the sheet unfolded and lying adjacent to one another in readiness for use; Figure 40 is a side view of the masking sheet of Figure 1 with the panels of the sheet overlying one another; Figure 41 is a perspective view of the masking sheet of Figures 1 and 2 with the panels of the sheet partially open; Figure 42 is a perspective view of a masking aid similar to that shown in Figure 3 having an additional, or intermediate, panel between the front and rear panels; Figures 43a, 43b and 43c are respective plan views of respective rear, front and intermediate panels of a hairdresser's masking aid incorporated in other embodiments of the invention; Figure 43d is a schematic view of the panels of Figures 5a to 5c lying one on top of the other in a partially overlapping arrangement; and, Figure 44 is a perspective view similar to Figure 3 of a hairdresser's masking aid constructed in accordance with another embodiment of the present invention.

Referring now to Figures 1 to 3, there is shown an elongate sheet substrate 1 which

constitutes a hairdresser's masking sheet comprising two rectangular panels 2 and 3 of substantially the same size and shape. Panel 2 comprises a substantially opaque, preferably white, polyolefin or polyester flexible sheet material and panel 3 comprises a substantially transparent polyolefin or polyester flexible sheet material. The edges 4, 4' of the respective panels that are in closest proximity to each other in the central part of the sheet are provided with respective semi-circular portions 6, 6' which depend from the respective edges 4, 4' and connect the panels at a common apex point of the semi-circular portions.

The semi-circular portions are preferably pivotable with respect to each other about the apex 7, that is to say they may be folded over each other about a common fold line as indicated by the dashed line 7 in the drawing of Figure 1. The marginal edges 8,8' of the semi-circular portions and the lateral sides 9, 9' of the lower edges 4, 4' are preferably formed flat (in the plane of the panel). Accordingly, panels 2 and 3 can be pivoted around apex 7 so as to bring the panels 2 and 3 toward one another and the edges 8 and 9 may be heat sealed with corresponding edges, 8'and 9'respectively to form a semi-circular shaped receptacle while leaving the surfaces of panels 2 and 3 unadhered to one another. This provides a receptacle at the lower edge of the panels having a volume that may act as a treatment substance reservoir. Optionally, a frangible seal 10,10'may be provided along the edges 4, 4' in the region of the receptacle to house a treatment substance in the receptacle.

The surfaces of panels 2 and/or panel 3 may be provided with securing means, preferably adhesive strips, which enable removable fixation of the masking sheet to

the hair and/or adjacent sheets.

As shown in Figures 2 and 3, panels 2 and 3 may be approximated about a pivotable portion 11, 11'provided along edges 4, 4' so as to unite the two panels either prior to use or in order to envelop selected strands of hair therebetween.

The panels 2 and 3 are of substantially equal area, as are receptacle halves 6 and 6'.

The sheet may be formed in a single operation, or selected components of the sheet maybe welded or coextruded to provide the above described features. The edges 5, 5' of the sheet furthest from the hinge 11, 11'define respective upper edge portions of the respective panels of the masking sheet when the panels are approximated as shown in Figures 2 and 3.

Figures 4-6 shows a sheet substrate comprising a receptacle similar to that of Figure 1.

Figure 4 shows panels 2 and 3, which are of substantially equal area and formed from similar materials as a substrate shown in Figure 1. Panels 2 and 3 are welded to one another along a common edge, or co-extruded, to form a transversly extending hinge 12. As with the masking sheet of Figures 1-3, the substrate shown in Figures 4-6 may comprise one or more securing means, for example adhesive strips by, which the substrate may be secured to selected strands of hair and/or adjacent sheets.

Two halves of a receptacle 13, 13'are located adjacent the hinge and are formed as a blister, preferably by heat forming. The panels 2 and 3 may be approximated by pivotal movement about the hinge and heat sealed to one another to form a reservoir.

The panels are preferably heat sealed on respective surfaces 14, 14'. that surround the

respective regions on the panels which form the reservoir. Treatment liquid may flow into the receptacle through a mouth portion 15, which opens into the region between the panels. Squeezing a blister 13 which contains a liquid treatment substance will cause the substance to flow out of the reservoir onto panels 2 and 3. If the envelope is closed, that is to say the panels are united and overlie on another, capillary action will allow liquid to flow between panels 2 and 3, thereby increasing the amount of treatment substance on the hair, or replenishing treatment substance after it is drained into the blister.

In use, strands of hair of a head of hair are selected and one of the panels 2 or 3 is place under selected strands of hair such that an upper margin 5,5'of the panel is located adjacent the scalp of the head. The selected strands of hair may be subsequently coated with a treatment substance, for example a liquid colouring substance and the panel 2 is folded about the hinge 12 and is superimposed on panel 3 with the selected strands of hair located therebetween. Where a securing means, for example an adhesive strip, is provided, the hair may be contacted with said strip, thereby securing the selected hair between the panels. The fact that one of the panels, preferably the front panel, is transparent, or is provided with a transparent window in the panel, enables a hairdresser to monitor the coloration process of the selected strands of hair without having to remove the envelope 1 from the hair or peal back a panel 2,3 in order to monitor the process. Further where one of the panels is substantially opaque, for example white, this provides a convenient colour over which to view the colouring process.

Figure 4a shows a similar sheet substrate to that of Figure 4. In the embodiment of Figure 4a panel 2 is provided with an adhesive strip 18, adapted to contact and secure to hair strands in use. Envelope sealing means 16 are additionally provided along the lateral side edges of the panels. These sealing means may be adhesive strips or a mechanical seal such as those found on food bags. In this latter case, seal 16 on one of the panels may comprise a raised ridge and the seal 16'on the other panel may comprise a ridge receiving trough. The approximation of seal parts 16 and 16'causes the ridge to enter the trough, thereby sealing the sides of the envelope, thereby preventing or reducing leakage of treatment substance. Seal 16 is shown running from the edges 5, 5'of the sheet, to the hinge 17, about which the panels 2 and 3 may pivot when surfaces 14 and 14'are sealed together.

In the aforementioned embodiments separation of the panels 2 and 3 is easily effected.

Each of panels 2 and 3 may be separately grasped and pulled apart, or the envelope may be scrunched between fingers in order, to separate panel 2 from panel 3.

Figure 7 shows a similar sheet to that shown in Figure 6. By contrast, Figure 7 shows a receptacle 13 containing a treatment composition. In this embodiment the receptacle is provided with a frangible seal 19 adjacent to the hinge 17 about which panels 2 and 3 may pivot. Furthermore, an apertured enclosure 21 is shown having an adhesive strip 22 enclosed therebetween. This feature will be discussed in more detail below in relation to the embodiments shown in Figures 14 to 20. In the embodiment of Figure 7 the surfaces 14 and 14'are shown permanently heat sealed together.

Figure 8 shows a sheet substrate 1 having panels 2 and 3, joined by a transversely extending hinge 23 about which each panel may pivot. An upper marginal portion 24 of the panel 2 furthest from the hinge 23 is provided with islands of elongate adhesive material 25. These islands extend inwardly from the adjacent margin 24 and channels 26 are provided therebetween. These channels are adapted to facilitate the conveyance of liquid from the central region of the panels toward the edge 24. Preferably, the pressure sensitive adhesive islands are slightly raised on the surface of portion 2, such that a slight space is provided between the panels 2 and 3 adjacent the adhesive islands. The dimensions of this space may be adapted to optimise capillary action so that the conveyance of liquid towards the margin 24 is maximised. It is particularly preferred that the edge 24, and the edges of other masking sheet substrates according the present invention, are adapted to abut the scalp during use, are less flexible than the rest of the panels 2 or 3. Such a stiffening of the margin provides greater ease of use and handling.

Prior to use, the adhesive islands may be covered with a cover strip (not shown) having a release coating in contact with the adhesive. In use, the cover strip is pealed from the adhesive so as to expose the adhesive ready for use. It will be appreciated that use of a cover strip facilitates stacking of sheets.

In a particularly preferred embodiment, one of the panels, for example panel 2 or 3, is less flexible than the other. This provides a greater support for the selected hair strands in use.

Figure 9 shows a side view of the substrate shown in Figure 8 formed into an envelope. A gap between portions 2 and 3 is illustrated to emphasise the space, which may exist between the panels of the envelope to facilitate capillary action of treatment liquid located between the portions.

Figure 10 shows a sheet substrate comprising panels 2 and 3. Panel 2 is provided with islands 25 of pressure sensitive adhesive and two substantially parallel strips of adhesive 27, 27'the strips of adhesive 27, 27'extend along the respective lateral side edges of panel 2 from panel margin 24, down to hinge 23. Adhesive islands 25 and strips 27, 27'may be provided on faces of both panels 2 and 3. In use, as panels 2 and 3 are approximated by pivoting about hinge 23, panel 2 contacts and adheres to panel 3 through adhesive strips 27. Adhesive islands 25 may be used to contact and secure selected hair strands between panels 2 and 3. Adhesive strips 27 and 27 not only secure panels 2 and 3 together, but further provide a seal against the leakage of any treatment liquids from the envelope in use.

Figure 11 is a side view of the masking sheet substrate shown in Figure 10. The substrate is shown folded so that adhesive strip 27,27'is almost in contact with adjacent panel 3. As with previous examples, the adhesive strips and islands may be provided with a cover strip having a release coating in order that the sheets may be stacked, for example, for transport or storage. Further approximation of panels 2 and 3 would lead to contact of the panels by the adhesive strips, thus removably securing panel 2 to panel 3.

Figure 12 shows another masking sheet substrate 1, having panels 2 and 3 joined by a transversely extending hinge 23 along a common edge of the panels. In this embodiment, both panels 2 and 3 are constructed from opaque material. However, panel 3 is provided with a substantially transparent window 28, in this case an elliptical window, in order that monitoring of the hair treatment is facilitated. Panel 2 is provided with islands of adhesive material 25 for securing hair to be treated thereto.

Figure 13 shows a perspective view of the partially folded sheet substrate of Figure 12.

Figure 14 shows another masking sheet substrate 1 in which the panels 2 and 3 are joined by a transversely extending hinge 23. In this embodiment panel 2 comprises an enclosure formed by a flap extension 29. The enclosure contains an adhesive strip 30, which is sandwiched between panel 2 and flap 29.

A row of equally spaced apertures 31 are formed in the flap 29 and extend across the boundary of the flap with the panel 2 defined by a transversely extending hinge 33.

The hinge 33 forms the top edge 5 of the panel, which in use abuts the scalp. The flap is folded back, preferably in contact with panel 2 and may be adhered thereto.

Alternatively, contact with the adhesive strip 30 keeps the flap proximate the face of panel 2. The hinge 33 may be heat formed, thus plastically deforming the hinge such that the flap folds back towards the face of panel 2 into the configuration shown in Figures 14 and 15.

Figure 16 shows the masking substrate of Figure 14 prior to folding the flap 29 and the placement of the adhesive strip. The apertures 31 are clearly seen to extend across the

transversely extending hinge 33.

Figure 17 shows a perspective view of the partially folded sheet of Figure 16.

Figure 18 shows the masking sheet substrate of Figure 16 with the adhesive strip 31 in place, prior to folding of flap 29 into contact therewith.

Figure 19 shows a perspective view of the partially folded substrate sheet of Figure 17, but with an enclosed adhesive strip as shown in Figures 14 and 18.

Figure 20 shows how hair 34 is contacted and adhered to the adhesive strip 30. The scalp 35 is here shown as a strip for convenience.

The embodiments illustrated in Figures 14-20 have particular advantages. Firstly, the adhesive strip 30 may be double sided. This allows strands of selected hair to be contacted and enveloped between panels 2 and 3. Alternatively or in addition, the opposite side of the adhesive strip may be used to contact adjacent masking sheet substrates or hair not selected to be treated that is outside the envelope. Thus, a single adhesive strip may be used to secure the sheet substrate in two discrete ways.

Furthermore, the toothed nature of the edge 32 of panel 2 may be used to gather and trap selected hair for treatment. This aspect shall be discussed in greater detail below with reference to Figures 22 and 23.

Figure 21 shows a masking sheet substrate 1, comprising panels 2 and 3. In this

embodiment, adhesive strips 36 and 37 are provided on opposite faces of the sheet.

Sheet 36, in use, is located outside the envelope and may be used to contact and secure the sheet substrate to adjacent substrates or hair located outside the envelope. The adhesive strip 37 may be provided inside the envelope and enables selected hair to be secured thereto.

Figure 22 shows another masking sheet substrate comprising panels 2 and 3 joined by a transversely extending hinge 23. In this embodiment, panel 2 is shown bearing an adhesive strip 37 of material. In this embodiment, the adhesive strip 37 is not necessary but optional. The adhesive strip may be provided for use inside or outside the envelope in use. Panel 2 is shown having toothed or comb portions 38, which form gaps 39 therebetween. The gaps are seen to converge towards the basent thé teeth 40.

The combed portion may be used to gather and optionally trap selected strands of hair for treatment. Thus, in use an amount of hair is selected and combed using the sheet substrate. Strands of hair are received by the gap 39 and moved towards the bottom of the gap, adjacent the base of the teeth 40.

As the gaps converge, the hair is forced together and becomes removably trapped in the gaps. This provides a securing means. However, adhesive may be provided in order to approximate panel 2 with panel 3 so as to envelop selected strands. It should be noted that the size of the gaps between the teeth may be adapted in order that an approximately predetermined amount of hair is trapped therebetween. This may be used in order that a predetermined amount of treatment substance maybe made up and applied to the hair in the knowledge that the amount of treatment substance used is

sufficient to treat the amount of hair gathered by the teeth.

Figure 23 shows a side view of an enclosed envelope formed from a masking sheet substrate such as that shown in Figure 22.

Figure 24 shows another masking sheet substrate 1 comprising panels 2 and 3 joined by a transversely extending hinge 23. Proximate the upper margin 41 of panel 2, there is provided a flap or strap 42, which is pivotly joined to panel 2 by a hinge 43. Strap 42 is provided with an end portion 44, which is in turn pivotly joined to strap 42 by hinge 45. Optionally, end portion 44 comprises an adhesive substance capable of contacting and adhering strap 42 to panel 2. In use, selected strands of hair are placed on panel 2, strap 42 is pivoted about hinge 43 such that the face of strap 42 contacts the face of panel 2, trapping the selected hair between strap 42 and panel 2. End portion 44 is then pivoted about hinge 45 and may be folded around the edge of panel 2 and brought into contact with the rear of panel 2 and secured thereto. Treatment substance may be applied to the hair and panel 3 approximated to panel 2 in order to form an envelope.

Figure 25 shows a sheet substrate similar to that of Figure 24. In this embodiment, the strap 42 maybe secured by end piece 46 directly to the face of panel 2. Similarly, end portion 46 may be brought into contact and secured to secure point 47.

In either of the embodiments shown in Figures 24 and 25, additional adhesive strips or islands may be provided on the face of panels 2 and 3 or on the face of the strap 42.

Figure 26 shows a perspective view of the sheet substrate shown in Figure 24.

Figures 27 to 29 show a sheet substrate 1 similar to that of Figure 12 comprising a window 28 of substantially transparent material. In this embodiment the panel 3 includes one or more indicia (not shown), which may comprise a logo or other produce identifier. The indicia may be in the form of a hologram. In a similar way to the embodiment of Figures 14 to 20, the sheet shown in Figures 27 and 28 comprises an enclosure formed by a flap extension 50 at the end of sheet 2 furthest from the fold line 23 with a double sided adhesive strip 3 0 sandwiched between the panel 3 and the flap 50. A flap extension 29 is also provided on sheet 2 and folded on to the interior side of the folded sheet along transverse fold line 33.

As can best be seen in the drawing of Figure 29, a row of elongate apertures 51 is formed in both the panel 3 and the flap 50 so that when the flap 50 is folded over the panel 30 along the transversely extending fold line 52 between the flap 50 and the panel 2 the respective apertures 51 in the flap and panel 3 are aligned in registration with one another. In this way the adhesive strip is capable of holding the flap 50 and panel 3 together to provide adhesive contact surfaces on both sides of the panel 2 in the apertures 51 for contact with both the flap 29 for holding the panels 2 and 3 together and to the scalp and/or adjacent strands of hair in use.

In the embodiment shown in Figure 28, the masking sheet comprises a receptacle 13 similar to that shown in the embodiments of Figures 1 to 7. In the arrangement shown

in Figure 28 the substrate is provided with a window are 52 on at least one side of the receptacle part of the masking sheet. The window area comprises a substantially transparent'material so that the contents of the receptacle 13 are visual to the hairdresser in use.

The hairdresser's masking sheets described with reference to Figures 1 to 29 may be formed singly, as previously described, or as a continuous web of masking sheets, as in the embodiment shown in Figures 30 to 36.

As can be seen in Figure 30, a continuous web 60 of hairdresser's masking sheetsl, according to a further embodiment of the present invention, comprises a plurality of adjacent sheets 1 joined together at their respective ends along transversely extending lines of separation 62. The lines of separation 62 comprise a series of perforations running along the marginal edge 24 of the panel 2 so that the panel 2 of one sheet can be readily separated from the edge of an adjacent panel 3 of the next sheet in the web.

The continuous web 60 comprises masking sheets similar to the sheets shown in Figures 12 and 13, that is to say with islands 25 of adhesive material close to the edge 24 of panel 2 and a transparent window 28 in the panel 3 for monitoring the hair treatment. In the embodiment of Figure 30 the panel 2 is further provided with a U- shape adhesive strip 64 on the same side of the substate as the adhesive islands. The adhesive strip extends transversely across the panel 2 adjacent to the fold line 23 between the panels 2 and 3 and at right angles along the side respective edges of the panel 2 a short distance from the fold line 23. When the panels 2 and 3 are brought together in use, the U-shape adhesive strip 64 contacts and adheres to panel 3 to form

a reservoir for treatment solution between the panels in the region 66 bounded by the adhesive 64. The panel 3 is provided with a second triangular shaped window 68 in the region of the panel 3 that overlies the reservoir region 66 when the panels are brought together.

The web 60 is preferably rolled as shown in the drawing of Figure 31 so that it may be enclosed in a box type container 70, as shown in Figure 32, and dispensed from a slit 72 in the box through which the free end of the web passes. In such an arrangement, the adhesive islands 25 and strip 64 are preferably provided with a release strip to prevent the adhesive adhering to other side of the panels when the web is rolled. The slit 72 is preferably provided with a blade or an edge over which the perforations may be positioned to enable the next sheet on the web to be separated foreuse.

The drawing of Figure 33 shows a single sheet 1 which has been separated from the web 60. In this drawing the adhesive islands 25 and strip 64 are provided with protective release strips 74 and 76 respectively. The adhesive islands are covered completely whereas one of the side edges of strip remains uncovered. Figure 34 shows the reverse side of the sheet to that of Figure 33 and Figure 35 shows the panels 2 and 3 folded together along fold line 23.

Referring now to Figure 36, in another embodiment of the invention the panels 2 and 3 are either formed separately and attached together, for example, welded or heat sealed together, to form a transversely extending hinge of the type previously described, or folded from a single sheet of material. Figure 36 shows the front panel 3

of a masking sheet 1 wherein the front panel comprises a laminate sheet of die cut metal foil, preferably 19 micron thickness, and clear transparent polyester film, preferably two layers of 12 micron thickness. The metal foil is preferably aluminium metal foil and is die cut to provide a substantially rectangular sheet measuring 225mm by 90mm. The aluminium sheet is provided with three die cut windows including a central and oval shaped window 80 in the centre of the sheet, a triangular shaped window 82 towards the bottom edge 84 of the sheet and a further oval shaped window 86 towards the top edge 90 of the sheet. The major axis of the oval window 80 is orientated in the longitudinal direction of the sheet while the major axis of the window 86 is orientated in the transverse direction of the sheet. Typical dimensions for window 80 are 85mm by 40mm, and 40mm by 20mm for window 86. All the windows are centrally positioned between the transverse lateral side edges of the sheet. A gap of 20mm is provided in the longitudinal direction of the sheet between windows 80 and 86 and a gap of 50mm between windows 80 and 82. A fold line 88 parallel to the top edge 90 of the sheet is coincident with the major axis of the window 86 and extends transversely between both transverse lateral side edges of the sheet.

The fold line 88 is positioned 30mm from the top edge 90.

The die cut aluminium sheet is laminated with a thin film of clear plastics material, such as transparent polyester, and the laminated sheet is folded along the fold line 88 so that the die cut window 80 forms a window of clear transparent material in the centre of the top edge 24 of the folded sheet as shown in Figure 37a In this embodiment the portion of the sheet between the fold line 88 and the top edge 90 is folded over onto the rear surface of the laminated sheet as shown in Figure 37b.

As mentioned above, the front panel 3 shown Figures 36 and 37a and b can either be formed separately and joined to a rear panel to of a same or similar or different material or front and rear panels may comprise adjacent parts of a sheet folded into two approximately equal size halves.

A suitable rear panel 2 for forming a masking sheet with the front panel 3 of Figures 36 and 37a and 37b is shown in Figure 38. In this embodiment the rear panel 2 is formed separately from the front panel 3 from a sheet of aluminium foil having a thickness of 19 microns. The rear panel 2 is the same shape and size as the folded front panel shown in Figures 37a and 37b and includes a folded top edge margin 92 where the sheet is folded over on itself in a similar way to the top edgeportion of the front panel 3 in Figures 37a and 37b to provide a stiffened double thickness region at the top edge margin of the sheet. The fold line, therefore, defines the top edge 94 of the folded sheet in the same way that the fold line 88 defines the top edge of the folded part of the front panel of Figures 37a and 37b. The folded margin 92 has a depth dimension in the longitudinal direction of the sheet of 20mm.

A plurality of adhesive islands 93 are provided along the margin 92 in side-by-side spaced relation. The islands are of a generally rectangular shape measuring 5mm wide by 10mm deep with a spacing of 3mm between adjacent islands with the first and last islands positioned approximately 13mm from the respective natural sides of the sheet.

The island 93 are preferably printed on the surface of the folded margin 92, alternatively they maybe provided by die cut apertures in the folded part of the sheet

with a strip of adhesive provided between the folded parts as previously described with reference to the embodiment of Figure 29. In this way both layers of the sheet material at the margin 92 maybe die cut so that a double sided adhesive tape can provide an adhesive surface or surfaces on both sides of the panel for securing the masking sheet to strands of hair located in the envelope and also to strands of hair on the exterior of the envelope. The adhesive surface on the exterior of the envelope, that is to say the rear face of the panel 2, maybe provided with a release strip (not shown) for selective removal to uncover the adhesive in readiness for use.

The folded top edge margin 92 increases the rigidity of this part of the sheet so that it is able sit upright at the roots of the selected strands without buckling. It is important that the folded margin 92 remains flat in use as the gaps between the islands act as liquid conducting channels which allow the treatment solution to be drawn towards the top edge 94 of the sheet by capillary action along the selected strands of hair. It is important that these channels do not become obstructed by creases or folds in use.

The opposite end of the panel 2 to the marginal edge portion 92 is provided with a substantially U-shaped adhesive strip 95, which extends along the entire bottom edge 96 of the panel and along the respective lateral sides. The adhesive strip is approximately 1 Omm wide and extends approximately 3 Omm along the lateral sides of the panel from the bottom edge 96. The adhesive strip 96 joins the rear panel to the front panel 36 along their respective bottom edges so that the panels 2 and 3 are substantially superimposed on one another to form a masking aid as hereinbefore described. The adhesive strip 96 is similar to the strip 64 shown in the embodiment of

the Figure 30 such that the region bounded by the strip provides a region for receiving excess treatment solution as previously described. In this embodiment the window 82 of the front sheet substantially overlies the region bounded by the adhesive strip 96 so that the contents thereof maybe viewed through the window 82 in use.

As shown in the drawing of Figure 38 the side parts of the adhesive strip 96 that extend along the lateral sides of the panel are champhered to provide a funnel shaped entry into the bag-like excess treatment pouch formed at the lower portion of the masking sheet.

Although the adhesive strip 95 is applied to the margins of the panel 2 when the panels 2 and 3 are joined together, it is to be understood that they do tot necessarily hinge about the lower edge of the enveloped defined by edges 84 and 96, but instead tend to hinge about a line running parallel to the bottom edge, defined at the ends of the adhesive on the lateral sides of the sheet, that is to say about 30mm from the bottom edge of the masking sheet.

Masking sheets having front and rear panels 2 and 3 as described in Figures 36 to 38 are, therefore, provided with 3 windows including a main window 80 for observing progress of the hair treatment progress over the majority of the length of the strands of hair, a second window 86 for observing the same process at the roots of the strands of hair being treated, and a third window 82 for observing the quantity of excess treatment solution that has drained into the reservoir defined at the bottom of the envelope.

The rear face of the folded top edge portion of the front panel 3, as shown from Figure 37b, maybe'provided with a silicone coating to prevent adhesion with the adhesive islands 93 on the folded portion 92 of the panel 2 so that the panels are easy to separate in readiness for use.

The panel 2 of Figure 38 may, as previously described, constitute part of the same folded sheet as the front panel 3, in which case the rear panel 2 may also be a laminate metal foil/polyester sheet. Alternatively panels 2 and 3 maybe metal foil, preferably aluminium foil, with the window areas 80,82 and 86 covered with a thin film of transparent polyester sheet material of the type previously described.

Referring mow to Figure 39, there is shown a hairdresser's masking aid 110 comprising two rectangular panels 112,114 of substantially the same size and shape.

The panels constitute adjacent parts of an elongate sheet substrate. Panel 112 comprises a substantially opaque, preferably white, polyolefin or polyester flexible sheet material. Panel 114 comprises a substantially transparent polyolefin or polyester flexible sheet material. The panels are joined together along a common edge 116 by welding or other means, for example by adhesive, to form a transversely extending hinge.

An upper edge portion 118 of panel 112, opposite the common edge 16, is provided with a strip of pressure sensitive adhesive 120. The adhesive strip 120 extends from one side of the panel 112 to the other slightly inward of an upper edge 122 of the

panel, opposite common edge 116, so that an adhesive free region 124 is defined between the edge 122 and the adhesive 120. An upper edge portion 126 of the panel 114, opposite the common edge 116, has a stiffness greater than the remainder of the panel 14 so that the edge portion 126 does not distort when the sheets are separated from each other in readiness for use.

The increased stiffness of the edge portion 126 is provided by increasing the thickness of the edge portion 126, for example by providing an additional layer of the same sheet material along the edge portion 126 to double the thickness and stiffness of the edge portion. The additional layer is preferably provided by folding the longitudinal edge of the panel 112 on itself along a longitudinal fold line at the edge of the panel as shown in the drawing of Figure 2. The dimensions of the edge portion 126 are preferably such that it completely overlays the adhesive strip when the panels are brought together.

As shown in Figures 40 and 41 the panels may be hinged about the common edge 116 so as to unite the two panels, either prior to use for ease of storage and/or transportation, or in order to envelop selected strands of hair in use. Similarly the panels may be hinged apart to separate the panels in readiness for use to receive selected strands of hair between the panels.

Prior to use, the panels 112 and 114 are separated in readiness for use by releasing the upper edge portion 126 from the adhesive 120 holding the panels together. The adhesive free region 124 provides a finger tab for the overlying edge portion 126 so

that the panels can be more easily separated. The stiffness of the edge portion 126 is such that the action of releasing the edge portion from the adhesive strip occurs without distortion, notably curling, to the upper edge portion due to stretching of the surface of the edge portion in contact with the adhesive.

Once the panels are separated, strands of a head of hair to be treated (not shown) are selected by the hairdresser and the panel 112 is positioned under the strands in a known manner such that the adhesive strip 110 is located adjacent the scalp of the head. The adhesive adheres to the selected strands, which are then coated by the hairdresser with a treatment solution, for example a liquid colouring substance. The panel 114 is then folded over panel 112 about the common transverse hinge and brought into proximity with panel 112 to close the envelope so fonned-as indicated in the drawing of Figure 2.

Panel 114 is held with respect to panel 112 by cohesive forces acting onpanel 112 due to the surface tension of the treatment solution on the panel 114. The fact that panel 114 is transparent enables the hairdresser to monitor the coloration process of the selected strands of hair without either having to remove the masking aid from the hair or peel back the panel 114 to monitor the process. Where the other panel 112 is opaque, for example white, this provides a convenient colour over which to view the colouring process. In this respect, and with reference to the orientation of the attached masking sheet, panel 114 may be considered a front panel and panel 112 a rear panel when the masking sheet is folded in the closed configuration of Figure 40.

Referring to now to Figure 42, in another embodiment of the present invention the

masking aid comprises an additional intermediate rectangular panel 130 of substantially transparent material. The panel 130 is substantially identical to panel 114 and comprises a substantially transparent polyolefin or polyester flexible sheet material. Panel 130 is joined to panels 112,114 in substantially the same way that panels 112 and 114 are joined together, that is to say along common edge 116 by welding or other means to form a common transversely extending hinge about which all three panels may be pivotally moved with respect to one another. The panels are arranged with respect to one another so that they may be superimposed one on top of the other when they are brought together.

The panel 130 enables additional strands of hair to be selected for treatment in addition to the selected strands enveloped between panel 112 and 114. Additional strands are selected once the treatment solution has been applied to the selected strands between panel 112 and intermediate panel 130 and the panels have been closed.

Once panels 112 and 130 have been brought together the hairdresser may apply a different treatment solution, for example a different liquid coloration substance, to the additional strands and then envelop the additional strands between panels 114 and 130 by bringing the panels together. The transparency of panels 114 and 130 enables both treatment processes to be observed by the hairdresser without removing the masking aid from the hair being treated.

Referring now to Figures 43 a to 43d, in another embodiment of the present invention

the panels 112 and 114 are joined together by adhesive. The first panel 112, shown in Figure 43 a, is provided with an additional adhesive strip 132 for joining the panels together. The adhesive strip 132 is substantially U-shaped and extends transversely along the common edge 116 of the panel 112 and part way along the lateral side edges 134 and 136 of the panel away from the edge 116. The adhesive strip 132 is provided on the same side of the panel as the adhesive strip 120. In embodiments where the greater depth dimension 135 of the rectangular panel 112 is, say, 120mm and the lesser width dimension 137 is, say, 90mm, the adhesive strip 132 may be 5mm wide along the major portion of the edge 116, may be lOmm wide along the lateral side edges 134 and 136 and extend, say, 30mm along the edges 134 andl36 away from the edge 116. These dimensions readily enable the panels 112 and 114 to be hinged apart when joined together by the adhesive strip 132. The width of the adhesive strip 120 may be 12mm and the width of the gap 124 may be 3mm.

In this embodiment the first panel 112 comprises a metalised polyester flexible substrate sheet material. The second panel 114 shown in Figure 43b comprises a rigid clear film material, preferably a transparent polyester material, that is coated with an ink or other suitable coating in the region 138 adjacent to the edge 116 of the panel 114. An uncoated triangular shaped part 140 is provided in the centre of the coated region 138 with the apex of the triangle positioned closest to the edge 116 of the panel. The triangle 140 provides a transparent window in the panel in the coated edge region 138.

The U-shape adhesive strip 132 of the panel 112 partially surrounds a region 142

adjacent to the edge 116 of that panel. When the first panel is joined to the second panel 114, with the panels 112 and 114 superimposed on one another as previously described, the partially enclosed region 142 provides a reservoir for holding treatment solution in use. When the panels 112 and 114 are joined together the printed region 138 overlies the reservoir region 142 so that, in use, the contents of the reservoir can be viewed through the window 140.

Although not present in the embodiment shown in the drawings of Figures 43 a and 43b, the edge portion 126 of the front transparent panel 114 may have a greater stiffness than the remaining part of the panel.

With reference to Figure 43 c, an additional intermediate panel 130 is shown, which, in a further embodiment of the present invention, is provided between the panels shown in Figures 43a and 43b. Intermediate panel 130 is substantially identical to panel 114 but instead of the printed region 138 the panel comprises a U-shaped adhesive strip 144 substantially the same as the adhesive strip 132 previously described with reference to the rear panel of Figure 43a. The adhesive strip joins the intermediate panel 130 to the front panel 114 in the same way that the adhesive strip 120 joins the rear panel 112 to the intermediate panel 130 along the common edge 116 so that the panels may be pivotally moved with respect to one another. The panels 112,114 and 130 have the same or similar external dimensions and are shown schematically in Figure 43d in a partial overlapping relationship. It will be understood that the individual panels shown in Figure 43 d are arranged one on top of the other when they are joined together with the panels effectively superimposed on one another.

It will be readily apparent to those skilled in the art that more than one additional (or intermediate) panel 130 may be provided in a masking aid of type described with reference to Figures 43a to 43c. For example, two additional panels maybe provided so that the masking aid comprises four panels mutually joined together along a common hinged edge so that three regions are provided for separately treating different strands of hair.

With reference to Figure 44, in another embodiment of the present invention the front panel 114 is divided into two parts 114a and 114b between the upper edge portion 126 and the common edge 116 to provide two separate regions for receiving separate strands of hair and different colouring solutions.

It should be understood that a number of embodiments are provided throughout the description above. It should be understood that each of the embodiments is not exclusive of the other, and combined features of different embodiments are envisaged within the scope of the present invention. For example, mixtures of straps, adhesive strips or islands maybe provided for any of the above-mentioned embodiments. Such securing means may be provided on the internal or external of the envelope in use. A plurality of reservoirs may be provided.