Reactive diluent for radiation curing of film-forming polymers

This invention relates to a reactive diluent mixture employed in a free radical polymerization of film-forming monomers which comprises between about 25 and about 90 wt. % N-vinyl lactam containing 6 to 9 carbon atoms and between about 10 and about 75 wt. % of a non-cyclic vinyl amide having from 3 to 7 carbon atoms which is employed in a concentration of between about 10 and about 50 wt. % based on total film forming monomers.