TTO ribbon has a very thin layer of dried ink on one side of a polyester film and a suitable printhead lubricant on the other side. The ink layer is either a mix of wax and resin or only resin. A wax/resin mix is often used in general purpose applications across most flexible film packaging environments. Using a resin only ribbon is more common in demanding applications where there may be an environmental impact such as extreme heat or where adhesion becomes a challenge from a chemical resistance perspective. The ribbon type recommended by most thermal transfer suppliers will depend on the individual application and the exact coding requirements.