Thermal transfer prints with the use of a ribbon. Heat from the print head melts ink from the ribbon onto special thermal transfer paper or synthetic label media that is specially treated for thermal transfer use. The label media does not directly contact the print head, as the ribbon is between the print head and the thermal transfer media.
The thermal transfer ribbon has a coating of wax, resin, or a combination of the two. When the heat from the print head is applied to the ribbon, the surface coating melts and adheres to the label, which cools quickly and produces an image that is more durable than those generated from direct thermal printers. The durability of the thermal transfer labels will depend partly on the selection of the ribbon and label media combination. Wax, which has a lower melting point than resin, is more subject to smudging, scratches, and damage. If you want the most lasting barcode labels, invest in a resin ribbon, or, at the very least, a wax/resin ribbon.
Unlike direct thermal printers, thermal transfer is not limited to one or two colors. For applications where you want to include more graphics (e.g., logo), the broader color options is a definite advantage to thermal transfer printing.
There are advantages and disadvantages to both thermal transfer and direct thermal printers. The type you choose will depend on your priorities, including functionality, print quality, image durability, and cost of ownership.
Direct thermal printers are slightly more economical to own because they don’t require a ribbon and the label media is generally less expensive than thermal transfer ribbons and media. However, the cost savings is not a benefit if you require printing that is less sensitive to conditions like UV light, moisture, heat, smudging, scratches, and chemicals. The direct thermal media lower cost advantage is offset by shorter print head life, as the print head is not protected by a ribbon and the label media directly contacts the print head. The direct contact causes abrasion of the protective coating over the print head elements, which causes earlier print head failure compared to thermal transfer printing. The imaging dye coating on direct thermal labels and paper is often insufficient to deliver lasting quality. The images will fade in the presence of sunlight or in the presence of high heat will turn completely black. You can, however, purchase direct thermal media that offers better protection, such as polypropylene, which is waterproof. Otherwise, special coatings only provide a limited degree of additional protection.
Thermal transfer printing has a somewhat higher total cost of ownership than direct thermal printers. You need to replace the thermal transfer printer ribbons, which aren’t required for direct thermal printing. The ribbons will vary in price, depending on whether you choose wax, wax/resin, or the high-end resin ribbons. Thermal transfer printing delivers high quality, lasting images that withstand heat, light, and extreme environmental conditions. You can also print with a wider array of colors, and on more types of media, such as synthetic films.
Before you make your decision on a barcode printer, consider your options, and the pros and cons of each thermal printing technology. If you need help, please contact us.