A layer of a liquid composition containing(A) a heat-activated latent polymerizing agent for 1,2-epoxides with(B) a light-sensitive compound having in the same molecule at least one 1,2-epoxide group and at least one chalcone or cinnamate group, or with a mixture of(C) a compound containing at least one 1,2-epoxide group together with(D) a compound containing at least one chalcone or cinnamate group,is heated so that the layer solidifies due to thermal polymerization through the 1,2-epoxide group, remaining, however, photocrosslinkable. The solidified layer is exposed in a predetermined pattern to actinic radiation, the parts so exposed becoming photocrosslinked through the chalcone or cinnamate unit(s) and hence insoluble. An image is produced which can be developed by means of suitable solvents.An example of a suitable latent polymerizing agent (A) is boron trichloride-N-methylpiperidine complex, and a suitable light-sensitive compound (B) is 1-(p-(glycidyloxy)phenyl)-5-phenylpenta-1,4-dien-3-one.