Abstract: A vesicular photographic material comprising a polymeric matrix containing a sensitizer which liberates gas when exposed to light, and a process for manufacture of said material. The polymeric matrix comprises a blend of polymethacrylonitrile homopolymer with another resin selected from the group consisting of vinyl polymers and copolymers; epoxy polymers; and copolymers with polyurethane segments. Improved photometrics, particularly film speed, are realized.