Patent ID: 6998005

Claim:
A method for forming a dye sublimation image in a thermoforming plastic substrate with a dye carrier having an image formed thereon of a sublimatic dyestuff, the method comprising: placing the image of the dye carrier against a first surface of the thermoforming plastic substrate to form a substrate-dye carrier stack; heating the substrate-dye carrier stack to a sublimation temperature; cooling the substrate-dye carrier stack; and providing a clamping pressure against the first surface of the thermoforming plastic substrate during the heating and the cooling and therebetween; wherein the clamping pressure is provided by: placing the thermoforming plastic substrate on a platen; covering the dye carrier, thermoforming plastic substrate, and at least a portion of the platen with a membrane; and applying a pressure differential across the membrane, wherein the clamping pressure limits warping of the substrate during the heating, cooling, and therebetween.