Marking fluorocarbon surfaces

Most fluorocarbon polymer surfaces (especially PTFE and FEP) have hitherto been considered unsuitable for marking by laser printing, which would have obvious attractions for marking such materials in high performance electric cables. It has now been found that such surfaces can be made receptive to laser printed markings. A reflective surface is first formed, preferably by incorporating white pigment into a fluorocarbon base, and a light-transmitting (preferably translucent) fluorocarbon layer is applied over it. The clear layer comprises ETFE or ECTFE, and when the reflective layer is based on PTFE or FEP a primer layer formed from a mixed dispersion of PTFE and ETFE or PTFE and ECTFE is preferably applied before the underlying PTFE composition is sintered.