TTR Components
TTR's are composed of four or five layering ingredients: Backcoat, PET film, Release Layer, Ink, and sometimes Adhesive Layer.

Backcoat
The backcoat is a specially formulated chemical coating that protects the printhead from the ribbon during the thermal transfer printing process. It comes into contact with the printhead and provides smooth travel and excellent heat transfer.
PET Film
This polyester film is the "carrier" for the ink, adhesive layer, and the backcoat. Essentially, the chemical layers that make up the ribbon are all applied to this base film.
Release Layer
This acts to bond the ink to the PET film during the coating process and promotes transfer of the ink to the label during the printing process.
Ink
This provides the printed image, and can contain wax, resin, or a mixture of the two.
Adhesive Layer
Added to DNP's resin ribbons, this is specially formulated to promote adhesion to certain types of labelstock.

Fiberboard Cores
Ribbons are usually wound on fiberboard cores. These cores must be manufactured, prepared, and stored carefully to optimize the quality of the ribbon rewind during manufacturing and to maintain the quality of the ribbon during use.
Leader
This protects the ribbon during shipping and facilitates the loading of the ribbon into the printer.
Trailer
Many thermal transfer printers have optical sensors to shut the printer off when the end of the ribbon is reached. Without the inclusion of a suitable trailer film, printhead damage can occur.