PURPOSE: To obtain the subject composition which is used for coating the surface of an amino resin molding, has a specified elongation according to circular disc method and a specified blister-free time and therefore can prevent blistering and crazing.

CONSTITUTION: 1mol of melamine powder or 1mol of melamine powder and cocondensation component in total is mixed with 1-2.5mol of formaldehyde comprising, e.g. an aqueous 37% formaldehyde solution or paraformaldehyde, and reaction is effected in an aqueous medium with a pH of 7 to 9 at 70-95°C to form an aqueous melamine resin solution having a resin concentration of 40-60wt.% and a turbidity point of 20-70°C. This solution is, e.g. vacuum-dried to give a powdery melamine resin. 100 pts.wt. of this resin is mixed with 0-10 pts.wt. organic or inorganic filler, 0-20 pts.wt. curing catalyst, 0-2 pts.wt. organic or inorganic pigment, 0-4 pts.wt. solvent or plasticizer, etc., in, e.g. a Henschel mixer to give the objective composition having elongation of 140-160mm according to circular disc method and a blister-free time of 16-28sec.