Photo-curable coating formulations which comprise a durable and/or red-shifted reactable hydroxyphenylbenzotriazole ultraviolet light absorber (UVA) are effectively photocured employing a combination of .alpha.-hydroxy ketone and bisacylphosphine oxide photoinitiators. The reactable UVA's are reacted into the coating upon curing. The combination of the photoinitiators bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 1-hydroxycyclohexylphenylketone is especially effective for this purpose.