Photograph: Rick Rizner

Portable printers cost more than their desk-bound counterparts, but if you have to print while you travel, you won't find a better printer than HP's $349 Deskjet 450wbt. The 450wbt runs on battery or AC power, and it weighs less than 5 pounds with its ink cartridges installed and its lithium ion battery attached. When closed, it's easy to carry, measuring 13 inches wide, 7 inches deep, and 3 inches thick. Its paper tray folds down and snaps shut to close the printer securely when it's not in use; the tray holds 45 sheets. The 450wbt doesn't have an output tray--finished print jobs simply slide out onto your desk, your car seat, or even a picnic table. The model we tested includes Bluetooth, but if you don't need that capability, you can buy the base model with USB 2.0, parallel, and infrared ports for $100 less.

In PC World's testing, the Deskjet 450wbt operated a little slower than most recently tested desktop inkjets. It printed text at 3.8 pages per minute, whereas general-purpose inkjets averaged 4.9 ppm. Text looked slightly grayish in spots, but letters were well formed and clean--on a par with most of the desktop inkjets we tested. (When we printed on higher-quality inkjet paper, the 450wbt printed heavy black text that bled a little.) It generated documents of mixed text and graphics at 0.8 ppm, compared with the average of 1.2 ppm. When we installed the optional $25 photo ink cartridge, the 450wbt turned out great glossy photos in both gray-scale and color. Color glossies looked somewhat oversaturated but had superb detail, while gray-scale photos looked equally sharp and showed realistic textures. Even the color documents we printed using lower-quality plain paper and the standard ink cartridges looked attractive, with realistic color and sharp focus, though there was some banding. The 450wbt fared poorly on line art, however: Narrow parallel lines bled together, and diagonal lines looked particularly jagged.

In our tests to gauge consumables costs, the 450wbt's ink costs matched those of the other mobile printer we tested, the Canon i80: 5.1 cents per black page (versus 5.3 cents for the i80), and 13.6 cents per page of color plus black (versus 13.4 cents for the i80).

One inconvenience to keep in mind: The 450wbt holds only two ink cartridges at a time, so to switch between printing documents and printing photos you have to swap cartridges and run the manual alignment procedure. A little plastic case that keeps the removed ink cartridge from leaking or drying out costs $15. Also, PC World didn't test the life of the lithium ion battery, but HP's specs say that it should last 350 pages and take only 90 minutes to recharge. An extra battery will cost you $79.

Upshot: The 450wbt makes printing high-quality graphics on the go extremely convenient.

Dan Littman