An impact printer that prints a line at a time. Printronix pioneered this technology in 1974. Line matrix and band printers are the surviving line printer technologies, but line matrix can print graphics, whereas band printers cannot. Line matrix resolution is in the 70 to 140 dpi range and speeds range from 400 to 1,400 lpm. Line matrix printers offer medium resolution, monochrome printing with a very low ribbon cost. They also provide high speed; for example, printing a three-part form at 1,200 lpm is equivalent to a 65 ppm page printer. Line matrix printers can exist in harsh conditions and are often found in warehouses and other industrial environments. A Row of Hammers The print mechanism is a row of dot hammers that is almost as wide as the page. The hammers are mounted on a shuttle that oscillates back and forth approximately two inches in a track. The hammers are magnetically released at the appropriate time and bang into a ribbon and onto the paper. See printer.