All dot matrix printers create characters on paper by striking an inked ribbon with a hard surface. Unlike typewriters, which use a similar mechanism, dot matrix printers do not have fixed character shapes or fonts. Instead, each individual character is formed by the arrangement of a series of pins. This allows dot matrix printers to be used for basic graphical printing and multiple fonts as well as basic text printing — but it gives the printout a characteristic “dotted” appearance. Dot matrix printouts often produce lower-quality text that can be difficult to read. In addition, dot matrix printers generally are noisier than inkjet or laser models.
The print quality produced by a dot matrix printer is significantly affected by the number and size of pins in the print head – even the best dot matrix printers generally can’t match the quality of inkjet or laser printers.
The simplest dot matrix devices use just nine pins to produce each individual character, creating a pixelized, blocky appearance. More complex printers use a larger number of smaller pins, producing greater detail and eliminating the characteristic look of dot matrix text. Common arrangements for these printers include dual 9-pin and 24-pin print heads.
