A donor element for use in laser thermal imaging has a layer which comprises an infrared-absorbing material, an image dye and a polymer matrix comprising a thermally degradable polymer and a non thermally degradable polymer there being an interaction between the infrared-absorbing material and the non degradable polymer to facilitate retention of the infrared-absorbing material in the donor element. The degradable and non degradable polymers are preferably copolymers both of which contain methacrylic acid as a monomer. The degradable polymer is preferably a copolymer of methoxyethyl cyanoacrylate and methacrylic acid preferably in molar proportions of from 1:1 to 12:1. The non degradable polymer is preferably a copolymer of methyl methacrylate and methacrylic acid, preferably in molar proportions of from 1:1 to 15:1. The element may be prepared from an aqueous solid particle dispersion which has been prepared by milling the components together in a ball mill.