Forms characters using row(s) of pins, 9, 18, or 24 which impact the ribbon on top of the paper. Also called pin printers.
The more pins, the smoother-looking the characters.
Most dot matrix printers have the characteristics below:
A dot-matrix y & an enlargement
Animation showing how columns of pins print the letter y (Credit: Bill Lewis)
Bi-directional -
prints left to right and also right to left
Tractor feed -
uses sprockets to pull continuous-feed paper
Friction feed -
uses pressure to pull single sheets
Advantages:
Inexpensive
Can do multi-copy forms
Disadvantages:
Can be slow
Loud
Graphics of low quality, if possible at all
Chain and Band Printers
Uses characters on a band or chain that is moved into place before striking the characters onto the paper.