Thermal transfer printing is the most widely used method for inhouse bar code label printing. A thermal print head is used to generate heat energy that in turn transfers the ink from a ribbon onto the label face stock, creating the required images. This method improves upon direct thermal printing in several ways. A wide variety of both paper and synthetic face stock materials may be used with both black and colored ribbons. Print quality is very high; the image is long lasting and durable. Bar codes can easily be read by both infrared and visible light reading devices.