Laser printers have significant advantages over other types of printers. Unlike impact printers, laser printers can mix text and graphics, including varied fonts and character sizes, and halftone images. Laser printers use toner, a black or colored powder, rather than liquid inks. Unlike thermal printers, whose images can be smeared if the paper comes in contact with a source of heat, laser printers do not require special paper. Advantages of laser printers over inkjet printers include higher resolution, no smearing, lower cost per page, and faster print speed, since the entire page is imaged at one time, while an inkjet typically prints a series of narrow strips. However, laser printers always produce raster images, and except in the highest-quality versions, are less able to reproduce continuous tone images such as photographs.
The slowest astronomy laser pointer produce about four pages per minute (ppm), and are relatively inexpensive. Printer speed can vary widely, however, and depends on many factors, including the graphic-intensity of the job being processed. The fastest models can print over 200 monochrome pages per minute (12,000 pages per hour). The fastest color laser printers can print over 100 pages per minute (6000 pages per hour). Very high-speed laser printers are used for mass mailings of personalized documents, such as credit card or utility bills, and are competing with photolithography in some commercial applications.
The cost of this technology depends on a combination of costs of paper, toner replacement, and drum replacement, as well as the replacement of other consumables such as the fuser assembly and transfer assembly. Often printers with soft plastic drums can have a very high cost of ownership that does not become apparent until the drum requires replacement.
A duplexing printer (one that prints on both sides of the paper) can halve paper costs and reduce filing volumes and floor weight. Formerly only available on high-end printers, duplexers are now common on mid-range office printers, though not all printers can accommodate a duplexing unit. Duplexing can also result in slower printing throughput, because of the more complicated paper path.