Abstract: A thin film forming method includes the steps of preheating a plurality of base plates placed at a first position, sequentially picking up the base plates one by one and positioning a picked-up base plate at a second position, heating the picked-up base plate at the second position so that a temperature of the picked-up base plate becomes approximately equal to a predetermined temperature, moving the picked-up base plate from the second position to a third position, and growing a thin film on a surface of the picked-up base plate at the third position.

Abstract: A method of producing a plastic sheet with a porous surface layer suitable for use as, for example, a recording medium on which characters and images are printed by ink jet or thermal-transfer printing method. The method comprises preparing a solution by dissolving two or more kinds of plastics having low levels of miscibility to each other in a solvent, applying said solution to a substrate, passing said substrate with said solution applied thereto through a liquid which dissolves said solvent but does not dissolve said plastics thereby solidifying said plastics, and drying said substrate with the solidified plastic layer. Preferably, two or more kinds of plastics having low levels of miscibility to each other include mainly a material A which is vinyl chloride or its compolymer and a material B which is acrylonitrile or its copolymer.