Abstract The chemistry involved in ultra-violet (uv) curing can be divided into two types: free radical and cationic. The more common formulations are cured by free radical polymerization of acrylate functional resins. Cationic polymerization involves the formation of a Bronstead or Lewis acid during the UV initiation which can then polymerize such functionalities as an epoxide or a vinyl ether. UV-curing adhesives have found acceptance in a wide range of industrial applications. These applications require many different formulations of UV adhesives, obtained by varying the oligomers, monomers, photo-initiators and additives used.