Choosing A Thermal Or Dot Matrix Printer Depends On Individual Application Requirements

There is an old adage that states – change for the sake of change is not good. As more and more thermal printers are introduced to POS applications, the question can be raised – are they necessary in every application or is there still room for dot matrix models?

Certainly, in some applications, a thermal printer provides benefits that warrant its integration. Its speed, reliability, and compact size are necessary to meet the requirements of certain POS systems. It would be an incorrect assumption, however, to believe that the dot matrix printer has gone the way of the dinosaur. In fact, in many POS systems, a dot matrix printer can still perform well enough to be used in lieu of a thermal model.

Dot matrix printers have advantages in applications that require multiple copies, such as credit card verification. Multiple copies are also extremely important in gaming applications, because it is legally required to keep a journal of all transactions. Dot matrix printers are more suited to these and similar applications because they are designed with a matrix mechanism that uses pressure to print. The pressure allows second copies to be clearly printed without any additional wear on the mechanism.

Thermal printers can be used in multiple copy applications as well, but there are disadvantages. The thermal process does not lend itself to multiple copies and as a result, if a thermal printer is used, it must print two separate receipts. Such a process creates additional wear on the mechanism, as well as uses more paper, which adversely affects its cost effectiveness.

Paper is also a determining factor in selecting either a dot matrix or thermal model in high heat applications. A typical example is a restaurant. The heavier stock of the paper used with a dot matrix printer is advantageous because it does not wilt under the high heat of a kitchen. In addition, regular paper absorbs the ink faster, reducing smudging or fading. A thermal printer's thin paper stock will wilt and smear under extreme temperatures.

Secondly, a dot matrix printer uses ink to print whereas thermal printers use the etching process. In restaurants, where cooks and other help with greasy hands constantly handle receipts, ink is preferred because it won't smear. There is a thermal paper available with a top coating that covers the etching so thermal printers can be used in such applications, but the coated paper can be as much as two or three times more expensive than standard paper.

Thermal Offers Better Speed, Smaller Footprint
The aforementioned examples are not to insinuate that thermal printers are being used just because they are fashionable. A thermal printer is preferred in today's POS world where speed and footprint are often times the most important features. They print at speeds as fast as 47 lines/second of text, compared to dot matrix models that typically print only three to five lines/second. Thermal printers also tend to be smaller, especially in their depth.

In addition to being faster, thermal printers are much quieter than dot matrix models. Such a feature is very important in upscale POS applications, such as fine restaurants, boutiques, and high-end department stores. Having a dot matrix model loudly print a receipt is not the image some retailers want to convey, especially if the printer is in a prominent location. If the printer is in the back, obviously noise is not a major factor.

Graphics capability is becoming more and more important in today's receipts. While both thermal and dot matrix printers have the ability to print logos, barcodes, and other graphics, they generally look sharper with a thermal printer. The etching and thermal paper are simply more conducive to such printing. In applications where branding and corporate image are factors, the thermal printer's enhanced graphics capability is important.

Because they are more advanced technologically, thermal printers can be designed into more sophisticated applications. For example, special software can be written that can conduct logging and reporting. In some cases, such as gaming, this technology eliminates the need to print multiple copies of the same receipt. The log and report can be printed out at designated times (usually daily, weekly, or monthly), and be used as back up rather than printing the extra copies. However, the gaming industry's printing preferences are still evolving.

Another benefit of thermal technology is its reliability. A dot matrix printer has a mechanism that drives the paper, a print head that moves from side to side, and a replaceable ribbon. As a result, it suffers much greater wear and tear than a thermal mechanism. Typically, a thermal model will print at least 30 million characters before needing to replace the head, compared to a dot matrix model, which typically prints from 300,000 to one million characters before a ribbon change is required. In stand-alone POS systems, a thermal printer's reliability can prove to be more desirable.

It is evident that the selection of either a dot matrix or thermal printer should be application-driven. Each offers distinct advantages in certain POS systems, and those advantages should be considered when selecting the best printer for each POS system developed. If a thermal printer is selected only because it is a newer technology, integrators will find themselves changing printers often, as printers will continue to evolve as long as technology advances.


Louis Hebert, Star Micronics America