Enhancement of the sensitivity of photopolymers is needed if photopolymers are to find more extensive applications in the printing and microlithography industries. A new concept is presented for sensitivity enhancement: the use of surface-activated microgels as a heterogeneous polymer matrix. The preparation of the microgels and their effect on the polymerization rate and the sensitivity are described. Examples are given of applications of microgel-based photopolymers as offset printing plates and photographic film.