A polymerizable Type II photoinitiator according to Formula: wherein: A represents a Norrish Type II initiating group and is a substituted or unsubstituted thioxanthone group; L represents a divalent linking group positioning the Norrish Type II initiating group A and the CR2R3-group in a 1-5 to a 1-8 position wherein position 1 is defined as the first atom in the aromatic or alicyclic ring of A to which L is covalently bonded and the position 5 to 8 is defined as the carbon atom of the CR2R3-group to which L is covalently bonded, with the proviso that L does not contain an amine; R1 represents an optionally substituted group selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an alkaryl group, an aryl group and a heteroaryl group; R2 to R6 each independently represent a hydrogen or an optionally substituted group selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an alkaryl group, an aryl group and a heteroaryl group, with the proviso that at least one of R2 to R6 represents a hydrogen; any two or three groups of the group selected from R1 to R6 and L may represent the necessary atoms to form a five to eight membered ring; and with the proviso that at least one of L, R1 to R6 and A is substituted with at least one ethylenically unsaturated polymerizable group selected from the group consisting of an acrylate group, a methacrylate group, an acrylamide group, a methacrylamide group, a styrene group, a vinyl ether group, an allyl ether group, an allyl ester group, a vinyl ester group, a maleate group, and a maleimide group. A represents a Norrish Type II initiating group and is a substituted or unsubstituted thioxanthone group; L represents a divalent linking group positioning the Norrish Type II initiating group A and the CR2R3-group in a 1-5 to a 1-8 position wherein position 1 is defined as the first atom in the aromatic or alicyclic ring of A to which L is covalently bonded and the position 5 to 8 is defined as the carbon atom of the CR2R3-group to which L is covalently bonded, with the proviso that L does not contain an amine; R1 represents an optionally substituted group selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an alkaryl group, an aryl group and a heteroaryl group; R2 to R6 each independently represent a hydrogen or an optionally substituted group selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an alkaryl group, an aryl group and a heteroaryl group, with the proviso that at least one of R2 to R6 represents a hydrogen; any two or three groups of the group selected from R1 to R6 and L may represent the necessary atoms to form a five to eight membered ring; and with the proviso that at least one of L, R1 to R6 and A is substituted with at least one ethylenically unsaturated polymerizable group selected from the group consisting of an acrylate group, a methacrylate group, an acrylamide group, a methacrylamide group, a styrene group, a vinyl ether group, an allyl ether group, an allyl ester group, a vinyl ester group, a maleate group, and a maleimide group.