Print head: The more pins on the print head, the better the quality of print. The most common are 9-pin and 24-pin. There is not much difference in cost between these two. Go with the 24-pin.

Characters per second: The higher this number, the faster your printer. These speeds can range from 250-1000 Cps. Remember these speeds are measured when the printer is in draft mode. Printing in near letter quality can slow you down from 50-250 CPS.

Carriage width: Dot matrix printers generally come in three sizes including standard, mid, and wide carriage. This determines what size paper you can use in your printer. What will you be printing? If you can answer this question, you can determine what size printer to buy.

Tractor feed or friction feed: Most printers come with both. Some come with a sheet feeder option which allows you to put a stack of single sheet paper in the printer at once.

Monochrome or Color: Some dot matrix printers can print in color. Others are color capable which means you can upgrade them to color later. Do you need color? If so, purchasing a color dot matrix printer could be a low cost alternative to other types of printers.