There has been some confusion between printing methods available for CD/DVD duplication. Disc printing methods are all adapted from paper printing processes; the two main processes are Thermal and Inkjet.
Direct Thermal Transfer
Both Thermal Processes use a ribbon coated with the pigments used for printing and they also use heat to adhere the color to the surface. Direct thermal transfer DVD/CD printers use heat and pressure to transfer pigments to the disc surface in desired areas, similar to those transfer letters you may have used as a kid. These printers cannot vary the saturation of the color. For example, with a black ribbon, printed text can only be black; it cannot be gray or have any gradients. These printers tend to be a bit faster and do a great job with single colors for text and simple line graphics but not for photos or full color images.
Thermal Re-transfer printers add one more step in the middle, hence “Re”. They apply the color to a clear ribbon using a ribbon made of colored panels. The image is “built” by layering different densities of color on top of one another and then “re”-transferring the image to the disc with heat and pressure. Colors for this type of printing can be made of wax-inks or dye-inks, leading us to the Dye-Sublimation process.
The dye sublimation process is almost exactly the same except the dye is applied to the clear transfer ribbon through sublimation. Now, channeling our high school chemistry knowledge you may remember that sublimation is when a compound goes from solid to gas without becoming a liquid. Because these dyes are sublimated, fine control of color saturation and color ratio can be achieved, resulting in a high quality photo prints.