TrueColors Multi-Panel Ribbons utilize heat to initiate a process called dye sublimation transfer, in which the color dye on the ribbon is vaporized into a gas and infused onto the card at the printhead station. Several types of ribbon panel combinations are available (some use a clear protective overcoat (O) panel which is applied to the entire card as the final printing step to protect the card image).The 4 Panel ribbon (YMCK) is designed for use with laminating printers in conjunction with a laminate patch. A clear protective overcoat (O) panel is not necessary because the laminate patch provides sufficient protection.