The Lexmark 4019 engine was introduced in several models of IBM's LaserPrinter series beginning in 1989. The 4019, featuring 300 dpi resolution and a print speed of 5-10 ppm, was an important entry to the printer market as the first desktop laser printer designed and built in the US. The subsequent 4029 models, released in 1991, were marked as the first printers introduced by Lexmark as an independent company. The 4029 family of printers, which ranged from 5-10 ppm, were all based on the 4019 engine. In 1993, Lexmark introduced a line of 4039 printers, featuring a new PCR-based cartridge, ranging in print speed from 10-16 ppm and having 600 dpi resolution. The 4049 engine, introduced in 1994, was featured in a new line of Optra network printers boasting resolution up to 1200 dpi and print speeds ranging from 12-16 ppm. The 4049 introduced yet another PCR-based cartridge. Overall, the printer/cartridge design is very similar between the 4019, 4039 and 4049. Some cartridge components are interchangeable, while others, such as toner and developer rollers, are not.
The development technology featured in Lexmark 4019/39/49 cartridges is very different from the technology featured in other cartridges, particularly the Canon-based cartridges: non-magnetic toner (Lexmark) vs. magnetic toner (Canon), doctor bar (Lexmark) vs. polyurethane doctor blade (Canon), polyurethane developer roller (Lexmark) vs. magnetic developer roller (Canon), and pure electrostatic development (Lexmark) vs. jump development (Canon). These differences in technology and components dictate a set of remanufacturing and cleaning procedures tailored specifically for Lexmark cartridges in order to effectively manage the cartridge and its components.