PURPOSE: To form a pattern composed of granitelike particles having a large particle size by making the temp. of a mold at the time of the bonding of liquid dropletlike particles higher than that of the mold at the time of the charging of a curable composition.

CONSTITUTION: The pipings 3 of a heating liquid medium are embedded in lower and upper molds 1a, 1b in the vicinity of the surfaces thereof and sprayable coating prepared by compounding a filler, pigment or the like with a thermosetting resin is diluted with a solvent and sprayed to the lower mold 1a by a spray gun 4 to bond liquid droplet like particles 2 to the lower mold 1a. When the sprayable coating is sprayed to the lower mold 1a heated to 70°C or higher, the dilution solvent of the liquid droplet like particles 2 is immediately volatilized and the thin layer composed only of the sprayable coating is formed. Next, the pigment is altered to prepare sprayable coatings which are, in turn, successively sprayed to the surface of the lower mold 1a to bond two or more kinds of liquid droplet like particles 2 having different hues and particles sizes to the lower mold 1a. Thereafter, the temp. of the lower mold 1a is lowered to 50°C to register the lower mold 1a with the upper mold 1b set to 50°C and a casting resin is injected in the molds. By this method, no liquid running is generated even when large liquid droplet particles are bonded and a varified granitelike pattern having a smooth surface can be developed.