The improved ink composition of claim 4, wherein the wavelength selective sensitizer is phthaloylglycine, 4(4-oxyphenyl)-2-butanone or an arylketoalkene represented by the formula ##STR36## wherein at least one of R1 and R2 is an aryl group; wherein when R1 is an aryl group, R2 is a hydrogen, alkyl, aryl, heterocyclic or phenyl group, the phenyl group optionally being substituted with an alkyl, ha