A composition for a protection layer for a thermal transfer ribbon which is free of solvents and which contains an acrylate oligomer or polymer having a functionality lower than or equal to 3, a di- or triacrylate monomer and a slip agent which are UV-crosslinkable in the presence of a photoinitiator, capable of forming, after coating on a backing film and after UV crosslinking, a protection layer having a thickness lower than 1 μm. The layer has a good adhesiveness and a low friction coefficient. The composition can particularly be used for the back (5) of a thermal transfer ribbon (1) applied on a surface of the backing film (2), the other surface of the film receiving at least one ink layer (3), while imparting flexibility and thermal and mechanical resistance to the ribbon (1).