Abstract: Photographic element designed to prevent duplication by contact copying with actinic light, formed from a synthetic organic polymer having a nitrogen gas permeability suitable for use as a vehicle in a vesicular film, and a light sensitive diazotype composition dispersed therein in which the diazotype composition includes a light decomposable diazonium salt and a coupler for forming a dye with said diazonium salt. Upon image-wise exposure and development, the light-struck areas are vesiculated and an azo dye is formed in the nonlight-struck areas. The image formed from the vesicules relative to the azo dye provide sufficient contrast for viewing by projected light but insufficient contrast for contact copying with UV light.