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Direct Thermal or Thermal Transfer?
“What’s the difference and how do I know which technology to use?”
Direct Thermal
A direct thermal printer requires special paper which is impregnated with a clear chemical film. When the paper is heated by a print head element, a chemical reaction occurs which turns the film black. Characters are formed by selectively heating elements on the print head array which covers the full width of the label stationery. Even after the thermal label paper has passed through a direct thermal printer, it remains sensitive to heat and ultra violet light. Serious label degradation can occur over time if the labels are exposed to these elements. Direct thermal printers do not, however, require any consumables such as toner or ribbons. They are ideal for receipt printing, and for short term labeling applications.
Thermal Transfer
In a thermal transfer printer the print head elements generate sufficient heat to release a pigment from an impregnated ribbon which is then pressed onto the label. Thermal transfer printers are slightly more expensive than direct thermal and require regular renewal of the print ribbon. Typically one roll of print ribbon will last for two rolls of paper. They can, however, print on any type of paper or other materials such as polyester and the labels do not degrade over time from Ultra Violet exposure or heat.
Both direct thermal and thermal transfer printers produce labels at about the same speed and cost.
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