Dye sublimation, or dye-sub, is the process of changing solid dye particles into gas using heat and pressure, bonding the dye particles with polymers and changing the dye back into a solid. Since the dye particles are designed to bond only with polymers, the dyed images will be brighter if the material to be dyed has high polymer content, such as a high percentage of polyester. This process impregnates the material with dye, which can be permanent.
Cotton fibers must be mixed with polyester or coated with a polyester layer before it can be dyed using dye sublimation. Canvas sold as cotton canvas for dye sublimation may actually be polyester that looks or feels like cotton. Like standard cotton canvas, canvas for dye sublimation can be stretched onto frames and used in displays and backdrops.
While canvas prints may be displayed on a stretched form, the canvas should be printed before being stretched. After the printing process is complete, the canvas can be trimmed and glued or stapled to a wooden frame or stretching bars. Some printing companies will print and stretch the canvas for their customers or will provide the printed canvas for the customer to stretch.
Dye sublimation printing systems are available in various sizes to fit the size of the item being printed. Some systems incorporate sublimation and curing units with the speed of an inkjet printer. Much like other printers, dye sublimation systems should be selected based on the needs of the purchaser. For example, a Velotex Express system does not require post-printing treatment of the fabric, thereby permitting the machine to print textiles unattended.