Compositions suitable for use as base coats and varnishes, preferably for use in combination with electrostatic of set inks printed onto plastics substrates, particularly polycarbonate compact discs. They contain a photopolymerisable material, a photoinitiator, an inorganic transfer agent and heavy metal salt, preferably a metallic carboxylate. They have a good shelf life and good adhesion after hardening with ultraviolet light.