thermal transfer ribbons derived from aqueous - based coating formulations which do not require the application of a separate backcoat to the substrate . backcoatings are self - generated on the untreated side of the substrate when the untreated side of the substrate contacts a remote portion of the top surface of the thermal transfer layer . the thermal transfer ribbons which self - generate backcoats comprise a flexible substrate and a thermal transfer layer which contains a water - soluble silicone block copolymer with blocks of silicone resin and water - soluble polymer . the water - soluble silicone block copolymer migrates to the top surface of the thermal transfer layer and generates a backcoat on the opposite surface of the substrate when the ribbon is wound such that the untreated surface of the substrate contacts a remote portion of the top surface of the thermal transfer layer . embodiments which incorporate both a water soluble silicone block copolymer and hydrophobic siloxane liquid or gum in the thermal transfer layer , for migration , are included .