All things being equal, higher resolution (more dots per inch) yields higher image quality, but all things are rarely equal. If a printer supports edge enhancement, the space between dots on the edges of text, lines, and solid areas will be filled in. This can have the same visual effect as doubling the resolution. But edge enhancement won't improve the quality of photos or graphics, so be sure you know whether a printer is printing at its claimed or enhanced resolution.

How a printer creates shades of a color also affects quality. If it uses different-size dots to create multiple shades for a given ink color (a technique called multilevel printing), it will usually provide higher quality than a printer that uses bilevel printing, in which each color in a dot has only two possible levels—all or nothing.

Make sure that the speed you're judging a printer by corresponds to the output quality you require. Just because a manufacturer claims a high print speed doesn't mean all types of output will print at that speed. Print speed can slow significantly in high-quality modes.

Be sure that you have the proper cable to connect your printer and computer and that it's long enough to suit your setup. Most printers today support USB, often without supporting the older parallel connection. If you have a computer that is not compatible with USB, pay careful attention to what a potential purchase supports. Shared printers connect directly to a network, so make sure your printer offers the right connection.

Some printers don't need memory, because they do all of their processing on computers. If you're considering one that allows memory upgrades, make sure it is equipped with enough RAM to store a full page at the resolution you'll be using. Some printers use additional memory for features that will speed up printing, such as the ability to process one page while printing another, or private printing, which holds a page in memory until you physically go to the printer and punch in an ID. Find out what additional memory does before buying.

Check out the capacities for the consumables your printer uses to get an idea of how often you'll need to change ink or toner cartridges or add paper. For a printer that has a different cartridge for each color, the cartridges will rarely run out at the same time.

Be sure that the printer can accommodate all of the paper sizes and types you'll be using. If you need to print on heavy stock, make sure the printer is designed to handle it. Consider whether you need duplexing capability (the ability to print on both sides of a page). If you'll be switching paper types on a regular basis, consider getting a printer with multiple trays, preferably a model that can select the right paper size or type for each of your print jobs automatically. Multiple output trays, collators, and automatic staplers are also worth considering for an office environment.