Thermal Printing
Direct thermal printing has been in use for over 40 years. It was first used in instrumentation applications (including the U.S. space program) and is now applied to many diverse applications requiring high reliability, high print quality, image stability, and low cost.

How it Works
Thermal paper is plain or bond paper coated with a heat reactive dye. When the paper is heated by a thermal print head the dye turns black and images are formed. This is represented by the figure to the right. Energy is applied to the paper by the thermal print head creating higher optical density or more "blackness." Energy is applied until the dot is fully developed (dashed line) and then the print head is turned off.

High Reliability
Unlike competitive print technologies, direct thermal print technology uses very few moving parts. In thermal printing the paper moves against a stationary thermal print head and is fed by a moving rubber roller or platen. Fewer moving parts result in a simpler print mechanism with higher product reliability.

Print Quality
Direct thermal printers routinely print at 8 dots per mm or 203 dots per inch true resolution. This means that there are 203 dots per inch horizontally on the print head and that the printer feeds paper at 203 steps or dot rows per inch. These results in outstanding print quality. Thermal technology is the print technology of choice for demanding applications like bar code printing where out of spec codes can result in penalties.

Thermal print also has a significant advantage over competitive scanning print technologies where the print head or cartridge moves across the page. The constant movement or scanning of the print engine frequently causes vertical dot misalignment. This can be significantly improved by printing from the same direction only (e.g. left to right), but this reduces throughput dramatically (by a factor of 2X).

Thermal Compared to Inkjet
Thermal printers have one consumable - paper! Inkjet printers on the other hand have inkjet cartridges, cartridge refill kits, and paper.

Based on internal tests, two-color inkjet printers have a limited printing life span. In the course of printing comparable receipts, with graphics, the print quality faded (unreadable) away after approximately 3K receipts. However, the ink remaining reading was 24 percent black and 67 percent red. In contrast, the thermal receipts never faded; they were bright and crisp through the 3K receipts and beyond.

Furthermore, Inkjet never has the print quality that you can get from TPG's two-color printers with ColorPOS technology. The graphics are streaky and of poor quality with an inkjet printer, whereas TPG's printers make your logos, graphics, and promotions look professional, making lasting impression to your customers.

With the industries best POS print quality and one consumable - paper - TPG's two-color printers with ColorPOS technology will keep your customers coming back and present your brand with bold, crisp printing every time.

Low Noise
Direct thermal printing is the quietest print technology. Drastically quieter than impact printers, thermal printers also produce sound in lower decibels than ink jet printers due to the absence of moving parts.

Print Speed
Direct thermal printing is the fastest printing technology available for POS printing. Considerably faster than other technology, thermal printers offer high reliability and high print quality. In the point of sale industry, print speed - or throughput - is measured in the time to print a 42-column or 3-inch print line. Impact and ink jet printers print at 3 and 6 lines per second respectively. Direct thermal printers print well in excess of 40 lines per second. Thermal printers print so fast that the industry measure for printing speed has evolved to capture the velocity of the paper movement while printing! (e.g. 130 mm/sec or 5 inches per second).

This high print speed gives the end user the opportunity to print more information on the customer receipt without adding to the customer's time at the checkout. Some retailers are using the print speed to bring added value to their applications by buffering data and printing a receipt sorted by frozen, dairy, meat, produce, etc. at the end of the transaction. Other will use the precious time to print special offers and targeted marketing messages.

Single Consumable
The retail and point of sale industry adopted direct thermal technology in the early nineties. In addition to benefits from high reliability, high print quality, low noise, and high print speed, retailers also enjoy thermal use of only one consumable - the paper. With direct thermal, end users no longer have to deal with operators changing the ribbon too soon (throwing ink away) or too late (receipts unreadable). With direct thermal, if there's paper in the printer, text and images will be sharp and of high quality.

Small Printer Size
Direct thermal printers are small. Since they don't use a scanning print technology, they use space efficiently. Their small footprint makes the printer easier to integrate into a workstation and allows the end user to have more room at the checkout for merchandise or selling.

Paper Types
Monochrome direct thermal papers are available today in a variety of prices and quality levels to serve customers and market needs best. This large selection can be broken down based on a combination of the following criteria: optical density, thickness and durability. Least expensive papers image with dark gray, offering poor optical density, while more expensive papers image a very deep and rich black. The thickness of the paper often depends on its base and will usually drive a higher cost. Thicker receipts are used by high-end retailers who want their receipts to convey a stronger brand image or by stores where the value proposition includes the total shopping experience. Durability is the last criteria. Top coated to enhance life expectancy; longer-life papers will resist elements like hand lotions and restaurant grease. They are often used in applications requiring long-term proof of purchase (5 to 7 years) and/or when the receipt may be exposed to harsh environment.