having incorporated therein at least one non carbon and non hydrogen atom and is not meant to be limited to the specific examples contained herein exemplary photoinitiators include triarylsulfonium complex salts aromatic sulfonium or iodonium salts of halogen containing complex ions aromatic onium salts of group via elements aromatic onium salts of group va elements and the like currently preferred photoinitiators include triarylsulfonium hexafluoroantimonate salts triarylsulfonium hexafluorophosphate salts mixtures thereof and the like the photoinitiator is present in the radiation curable composition in conventional amounts typically ranging from about 0 1 to about 15 by weight based on the total weight of the composition suitable radiation curable compositions are disclosed for example in u s pat nos 4 874 798 4 593 051 and 4 818 776 the entire disclosure of each of which is hereby incorporated by reference in addition the radiation curable composition can include a pigment capable of imparting color to the threadline the pigment can be an organic or inorganic pigment or a mixture thereof as known in the art useful inorganic pigments include without limitation metallic oxides iron titanium zinc cobalt chromium and the like metal powder suspensions gold aluminum and the like earth colors siennas ochers umbers and the like lead chromates carbon black and the like and mixtures thereof useful organic pigments include without limitation animal pigments rhodopsin melanin and the like vegetable or plant pigments chlorophylls carotenoids such as carotene and xanthophyll flavanoids such as catechins flavones flavanols and anthocyanins flavanones leucoanthocyanidins flavonols indigo and the like synthetic organic pigments phthalocyanone lithos toluidine para red toners lakes and the like and the like and mixtures thereof 0044 fig3 illustrates a cross sectional view of coating apparatus 20 of fig1 taken along line 3 3 coating apparatus 20 includes a horizontally split.