Process for preparing a mask for sandblasting

Claim 1

A process for preparing a mask for sandblasting, which comprises the steps of: (a) interposing a liquid photopolymerizable composition layer between a destroyable retainer film layer strippably attached onto the lower surface of a support film layer and a transparent soluble peel-aid film layer superimposed on a transparent protective film layer, thereby to form a photosensitive element, said transparent soluble peel-aid film layer having a peeling resistance of 10 g/cm or less against the transparent protective film layer and being soluble in an aqueous developer; (b) image-wise exposing the photosensitive element on its side of the transparent protective film layer through an image-bearing transparency to convert the liquid photopolymerizable composition layer to a layer having polymeric image portions and non-polymeric image portions; (c) stripping the transparent protective film layer from the transparent soluble peel-aid film layer; and (d) washing away with the aqueous developer the transparent soluble peel-aid film layer and the non-polymeric image portions of the layer having polymeric image portions and nonpolymeric image portions, thereby to provide polymeric image portions having their respective upper ends connected to the destroyable retainer film layer on its lower surface and having their respective free lower ends to be attached onto the surface of an article for sandblasting, said support film layer being adapted to be stripped from the destroyable retainer film layer while maintaining adherence of the destroyable retainer film layer to the respective upper ends of the polymeric image portions, said destroyable retainer film layer being adapted to be destroyed by sandblasting.