-Printers use various technologies to print text and images on paper.Thermal printing, for example, uses heat to transfer coloured ink onto a page or to change the colour of the paper itself. As part of standard office equipment, your company may have several thermal printers. If your company prints colour photos, a thermal-based dye sublimation printer may be used to produce high-resolution images.
Thermal printers come in two main varieties: one produces monochrome output, and the other prints in color. The first type draws specially treated paper across a row of tiny electric heating elements. If the element is hot as the paper moves over it, the paper turns black at that point; otherwise it stays white. As the process uses no ink, the mechanism is simple and durable — maintenance simply involves changing the paper. The dye sublimation thermal printer uses a ribbon containing three colored ink panels, each in a series, plus a fourth clear panel. Each panel is the same size as the printed page. Heat causes the solid ink to sublimate, or turn to gas without first becoming liquid. The ink bonds to a specially coated paper. The final clear panel seals the colors in place, producing a dry, durable full-color image of photographic quality.
Monochrome thermal printers are built into many cash registers, printing calculators, and label machines. A thermal receipt printer is also used by credit card readers. Thermal technology is an improvement over earlier inked ribbons used in office equipment, which occasionally jammed and were difficult to replace. Thermal printers were used in some of the first fax machines, but many have since switched to inkjet or laser technology for higher print resolution.
Some desktop photo printers employ dye sublimation technology, which produces high-quality prints in a matter of seconds. Although some photo
printers use inkjet technology, the finished product must be allowed to dry before handling; however, the dye sublimation process produces dry prints that do not smear. Thermal photo printers range in price from less than $100 to well over $1,000.
Coffee mugs, T-shirts, and other items with a custom photo or graphic design are made by novelty shops. These items have a special coating that allows coloured ink from a dye-sublimation thermal printer to be used on them. The basic process is the same as for photo printing, but the print mechanism has been modified to accommodate the novelties.
