Abstract: A method of producing a heat sealable label comprises the steps of: (i) providing a textile substrate which is of synthetic polymeric fibres and which is provided on one of its faces with a heat sealable adhesive, (ii) applying to the other face of the substrate a curable resin system, (iii) effecting cross-linking of said curable resin system, (iv) printing on to said cross-linked resin system a uv curable ink in the form of the desired marking, and (v) effecting uv curing of said ink. The ink incorporates monomer components which during the uv curing of step (iv) covalently bond to the cross-linked resin system.