Abstract: An optical fibre, comprising a glass core 10 surrounded by a glass cladding (11) of lower refractive index, is provided with inner and outer relatively high modulus plastics layers (12 and 14) spaced apart by a relatively low modulus layer 13. The low modulus layer is applied from an aqueous dispersion, and is dried but not sintered. This leaves the layer (13) in a form in which it has little adherence to the underlying inner plastics layer (12), thereby enabling the outer layer (14) to be readily peeled by mechanical means.

Abstract: A coating system for individual glass fibers of a lightwave communications system has improved strippability, particularly in situations where a group of such fibers are arrayed together in what is known as a ribbon. A preferred embodiment includes two layers (primary and secondary) of polymeric materials surrounding the glass fiber. The primary layer comprises an oligomer (50-80% by weight), a diluent (15-40% by weight), and additives (5-35% by weight). The oligomer comprises polyol "A," diisocyanate "B," and a hydroxy-terminated alkyl acrylate "C" having the structure C-B-A-B-C. At least one of the additives contains a non-crosslinked hydrocarbon component (1-20% by weight) having a structure R.sub.1 --(R).sub.n --R.sub.2 ; where R.sub.1, R.sub.2 comprises an alkyl group or an OH group, and R is a combination of C, H or C, H, O.