Abstract: A mask element for selective sandblasting comprising a support film layer and, superimposed thereon in the following order, a retainer film layer of a water-insoluble cellulose derivative and a photoresist layer of a pattern mask, said photoresist layer of pattern mask being adapted to adhere to the surface of an article body to be engraved with a strength such that the mask is not detached therefrom during sandblasting. By the use of the mask element of the present invention, a pattern exactly corresponding to that of the mask, even if it is very fine, can be engraved on an article body nicely.

Abstract: A process for preparing a mask for sandblasting, in which there is employed a transparent soluble peel-aid film layer superimposed on a transparent protective film layer to cover a liquid photopolymerizable composition layer. According to the process, the protective film can be readily stripped and a mask for sandblasting which has a strong adherence to articles to be engraved can be produced efficiently without occurrence of troubles, such as chipping of high-precision portions, e.g. fine dots and lines, of polymeric images.