dot matrix printer A printer that creates each character from an array of dots that are usually formed by transferring ink by mechanical impact. It may be a serial printer, printing a character at a time, or a line printer.

The serial printer has a print head containing typically 9, 18, or 24 electromagnetically operated styluses. The head is mounted on a carriage that is moved along guides so that it travels parallel to the paper and the position of the line to be printed. The styluses are selectively operated to build up alphanumeric characters and other shapes from a matrix of small dots. The generally available speed range is 100–400 characters per second (cps) for print of data-processing quality, and up to 100 cps for a higher-quality character. Some dot matrix printers include the ability to print in seven colors using a multicolor ribbon. Once the most widely used type of printer, dot matrix printers are now mainly used where multipart stationery is required.

dot ma·trix print·er • n. a printer that forms images of letters, numbers, etc., from a number of tiny dots.