Three corm urethane actylate resins (functionality 2-4) were dild. with trimethylpropane triacrylate and photopolymerized under UV light (12 mW/cm(2)) in presence of 1-hydro-xycyclohexyl-phenyl-ketone in 0.25-1.0 mm thick layers. The max. temp. 32-116 degrees C was achieved after 10-25 s.