Before you decide on which portable printer evaluate your printing needs.
Which is more important? High quality output, print speed and weight or a combination of these factors.
If you need portability, then evaluate the your travel situation. If it is between home and office, then consider low cost but high quality desktop printers from Epson, HP, Canon, Lexmark, etc…
If you do a lot of traveling to other cities, decide on the level of detail that the printer can provide, and determine whether the places you are traveling to have office services for printing. Many hotels offer such services. This might be less hassle than dragging along a printer.
Small size can be emotionally appealing, but may not work for your situation. If you really don't need portability, then stay away from portable printers unless you have a real need to purchase one.
If you decide on getting a portable, well… What to look for?
Look speed and text quality. Keep in mind that weight, battery power, and size also count much more than in desktop printer shopping. You should also consider accessories and cost of the ink cartridges. If you are on the company budget, then price might not be much of a factor.
Thermal transfer models tend to be smaller than inkjets but with lower image quality, slower print times and significantly higher cost per page. Both monochrome and color printing are possible depending on what kind of cartridge/ribbon you buy. In general, the cost per page for both text and color will be higher for portables because their small cartridges cannot print that many pages.
So, look at the specifications and review the size and weight of the portable carefully.
Since portables run on battery power, battery life is a key consideration if you need to print more than a few pages at a time. A standard Nickel-Cadium (NiCad) battery can print around 90 pages on one charge and can be recharged without removing it from the printer. A less common kind of battery is the Nickel Metal Hydride (NiMH) which lasts longer but takes longer to recharge. Not all printers include the battery in the price so be aware of that if you are comparison shopping.
Check out the size of the sheet feeder. Those printing several pages at once will want a sheet feeder so you don't have to manually feed each sheet. Feeders can handle 5-80 pages, and some also handle transparencies and envelopes.
Is there an infrared (IR) port. An IR port allows you to send commands to the printer without it being connected by cable to your computer.
Ink cartridges can be expensive, so if costs matters price the cartridges and get an idea how many pages they will last.
Some examples of portable printers are the Pentax thermal printers, which weight about a pound and costs around $300. The HP DeskJet 450 is a mobile thermal inkjet and costs around $250, weights about 4 pounds and will print about 500 pages a month with decent print quality of 1200 dpi or greater. Another interesting product is Canon's portable i70, you can make glossy hard copies of your digital-camera shots of mountain — or you can make prints to give to prospective real estate buyers without leaving your car. About the size of a notebook PC, the AC- or battery-powered printer weighs just 4.5 pounds and costs around $250 without the battery.
