Dot matrix - which are also referred to as impact printers - have been in use for decades, partially because of their reliability and lower cost of operation. They are cheaper to purchase than laser printers, don't deplete ink cartridges quickly like inkjet models (dot matrix printers use longer-lasting ribbons instead), and are very reliable. They are generally smaller than laser printers but can be larger or smaller than inkjet printers depending upon the particular model.

In the past I owned two dot matrix printers, both made by Okidata. They never needed a ribbon replacement, had any major problems, or needed any repairs while I owned them, unlike the inkjet models I have owned. Their print quality wasn't especially good, but it was quite readable. I eventually couldn't keep using them because the computers they were used with failed and they didn't use the same type of printer port as modern computers do. However, plenty of dot matrix printers are available which do use modern printer ports.

Some drawbacks of dot matrix printers is that it may be harder to get parts or ribbons for some of them because of their age (but you can buy them new to eliminate this problem, although it is more expensive), and their print quality isn't as good as that of inkjet and laser printers. They are mostly good for text, not graphics, so they are more popular for business applications and word processing. They are also noisier than many inkjet and laser printers.

When purchasing a dot matrix printer, make sure the ribbons for it are still available and that it uses a printer port which is compatible with your computer. Most modern computers have parallel-type printer ports, while older computers had a variety of port types.

It may be unsafe to use some older Tandy dot matrix printers with newer computers. According to oldskool.org, some models (such as the DMP 107, 133, 440, LP 1000, and others) can cause damage to newer computers if connected to them, and a few other problems may also occur if that doesn't happen.

Dot matrix printers use tractor-feed paper, which has rows of holes down each side so that the printer can pull them in. The rows of tractor feed holes can be torn off if necessary (they are perforated). This paper may also be referred to as "continous feed paper" or "computer paper". It is available in office supply stores like Staples and OfficeMax.

Most dot matrix printers only print in black & white, but a few models have been made by Panasonic and Epson which can print in color or be upgraded to have color capability.

While some dot matrix manufacturers no longer exist or now concentrate on producing inkjet models, a number of brands still produce them. Okidata (okidata.com) still makes models such as the ML-186 and ML-320 Turbo. Lexmark offers several dot matrix models, but refers to them as "Forms Printers." Citizen (citizen-systems.com), Star Micronics, Panasonic, and various other brands still make them as well.