A thermal printer generates images by pushing electrically heated pins against heat-sensitive paper. Basic thermal printers are inexpensive, but the print quality is low and the images tend to fade over time. Self-service gas pumps often print gas receipts using a built-in lower-quality thermal printer.
Two special types of thermal printers have high print quality. A thermal wax-transfer printer generates rich, nonsmearing images by using heat to melt colored wax onto heat- sensitive paper. Thermal wax-transfer printers are more expensive than ink-jet printers, but less expensive than many color laser printers.
A dye-sublimation printer, sometimes called a digital photo printer, uses heat to transfer colored dye to specially coated paper. Most dye-sublimation printers create images that are of photographic quality. Professional applications requiring high image quality, such as photography studios, medical labs, and security identification systems, use dye-sublimation printers. These high-end printers cost thousands of dollars and print images in a wide range of sizes. Most dye-sublimation printers for the home or small business user, by contrast, typically print images in only one or two sizes and are much slower than their professional counterparts. These lower-end dye-sublimation printers are comparable in cost to a photo printer based on ink-jet technology. Some are small enough for the mobile user to carry the printer in a briefcase.