a thermal dye transfer printing process for making transparent prints , which comprises bringing a dye - bearing donor ribbon in contact with a dye - receiving polymer print sheet at a print zone , supporting both materials on a backing support in said zone and contacting the donor ribbon with a print head for image - wise heating the ribbon and cause dye transfer to the print sheet , wherein the rear side of the print sheet is uniformly heated on a drum after removal of the sheet from the backing support , thereby to reduce curling of the sheet caused by the image - wise heating of its front side .