A mask is described for forming an image on a substrate. The mask may be selectively applied to a radiant energy sensitive material on the substrate. Actinic radiation applied to the composite chemically changes portions of the radiant energy sensitive material not covered by the mask. The mask and portions of the radiant energy sensitive material are removed using a suitable aqueous base developer. The mask is composed of aqueous base soluble or dispersible polymers and light-blocking agents.
