Description of the Prior Art In industrial use, transparent material is decorated by printing, coating, coloring, lacquering, gilding, etc. In all aforementioned cases, a flat, two-dimensional decor is involved. Holography is limited in use due to its increased technical and manufacturing demands. Foils provided with special lenticular screens allow for several methods of creating three-dimensional effect of which, in practice, the principle of patterned foil was used pursuant to the Czechoslovak patent No. 248189, on the basis of which lines originate which seem to be situated deeper in the space i. e. behind the foil plane.

In this case, one may speak about a three-dimensional effect which is limite, however, to a decor consisting of regular vertical lines or (as applicable) vertical lines combine with usual planographyprinting.

Summary of the Invention The three-Dimensional decor for flat transparent materials pursuant to this Utility Model allows for creating a broad range of three-dimensional patterns apparently located both in front and behind the relevant surface plane. In this case, transparent materials include foils and sheets of organic or inorganic glass. To create a decor with three-dimensional effect, it is necessary that the face of such transparent materials is provided with cylindrical lenses whose focus points lie in the plane of the reverse side of the materila applied. To achieve a three- dimensional pattern, the reverse side is provided with a screen the individual elements of which are based on the patterns to be obtained, yet transformed in a certain manner: their height dimensions, i. e. the dimensions parallel to the linearity axis of the optical screen, are not transformed, while their width dimensions, i. e. the dimensions perpendicular to the linearity axis of the optical screen are shortened so as the overall width of the pattern to be transformed is reduced to 95-105 % of the spacing between the individual elements of the screen. If the height dimensions are reduced to 95-99.9 %, the pattern appears to be behind the plane of the material while, upon reduction between 100.1 to 105 %, the pattern protrudes in front of it. As a general rule, the smaller is the spacing between the individual elements of the reverse side screen and the optical screen, the greater is the three-dimensional effect obtained and vice-versa.

Under application of the above described principles, an unlimited range of three-dimensional patterns may be created. By combination of reverse side screens of different density, an optical effect of nets extended one behind another in the three-dimensional space or various concave or convex bodies etc. may be created.

Reverse side screens may be combine with normal planography print to stress, in a more expressive manner, the three-dimensional effect of the decor. This combination may be achieved in several ways. First, the assembly of planography print and reverse side screen may be achieved using the usual procedure of painting out in the manufacture of original. Another possibility consists in first printing the planography print and, subsequently, the reverse side screen on the reverse side so that, viewed from the front side, the three-dimensional decor will appear only on places free of the planography print. Yet another possibility consists in the completion of planography print on the front side of the material by means of stickers or direct printing which requires, due to a certain unevenness of the surface material used for lenticular screens, the selection of an appropriate printing technique such as silk-screen printing or tampon printing.

Description of the preferred Embodiment Fig. 1 shows a three-dimensional pattern in the form of a square standing on its edge. It is our intention to create a three-dimensional decor involving a network of such squares appearing as if situated behind the foil's plane. Fig. 2 shows one of the elements comprising the chosen decor drawn following to transformation completed in accordance with the principles as desribed above. It is evident from the figure that any height dimensions have been preserved while the width has been reduced to approximately 95 % of the spacing between the individual elements of the optical screen. Fig. 3 shows a schematic view of a portion of the transparent material including the back-face screen 2 and the resulting pattern 3 creating the three-dimensional decor.

It is evident from Fig. 3 taht the density of cylindrical lenses creating the optical screen 1 is differnt from that of the reverse side screen 2. Since we desired to create a three-dimensional pattern appearing as if located behind the foil's plane, all elements have been transformed so that their width is by approximately 5 % shorter than the width of the cylindrical lenses creating the optical screen 1. The resulting three-dimensional pattern 3 makes the impression of a three-dimesional effect when viewed, with each eye, throgh the optical screen 1 from a different viewing angle.

Applications of the Utilitv Model Three-dimesional decor for flat transparent materials may be used for consumer goods packaging, materials intended for use in design of industrial products, book envelopes, CD, LP, video-cassettes, in polygraphic industry, publicity, architecture and in applied art.