Compounds of formula (I): {where n is a number from 1 to 6; R.sup.3 is hydrogen, methyl or ethyl; A represents a group of formula --[O(CHR.sup.2CHR.sup.1).sub.a].sub.y--,--[O(CH.sub.2).sub.bCO].sub.y--, or --[O(CH.sub.2).sub.bCO].sub.y--,--[O(CHR.sup.2CHR.sup.1).sub.a]-(where one of R.sup.1 and R.sup.2 is hydrogen and the other is hydrogen, methyl or ethyl); a is from 1 to 2; b is from 4 to 5; y is from 3 to 10, Q is a residue of a polyhydroxy compound having 2 to 6 hydroxy groups; and x is greater than 1 but no greater than the number of available hydroxyl groups in Q} and esters thereof are useful as photoinitiators for the preparation of energy-curable compositions, such as printing inks ##STR00001##