Portable printers are small, battery-powered printers designed for computer users on the go. Barely wider than the paper on which they print, portable printers can easily fit in a briefcase alongside a notebook computer. These units can weigh about one pound, and are capable of printing documents, envelopes or acetates.

This buying guide is designed to help you find the best portable printer for your travels. You can choose to read this guide from beginning to end, or jump directly to a section of interest by clicking on the links above.

Types of Portables

Portable printers work in one of three ways. Thermal transfer printers work much like a typewriter, using heat and pressure to transfer images from a ribbon to the page. Ink-jet printers use small cartridges of liquid ink, spraying very fine drops through a nozzle to create images.

Thermal printers operate like older fax machines These models use heat-sensitive, which is marked with a small heating device.

The main advantage of thermal and thermal transfer printers is that they can be very small. The smallest thermal printer weighs only 14 ounces, while the smallest thermal transfer printer weighs only 1.1 pounds. In contrast, ink-jet printers start at about 2.4 pounds.

On the other hand, ink-jets generally produce much better output than thermal transfer and thermal models. Ink-jets can produce decent images, particularly if very smooth paper is used. Thermal transfer machines often leave large horizontal bands on dark areas, while thermal printers require a special type of paper.

Most portable printers come with drivers to work with DOS or Windows applications. In most cases, you will have no trouble printing as long as your notebook computer has a serial or parallel port.

However, only a few portable printers work with Macintosh Powerbook computers. In most cases, you will need to first purchase a Mac-compatible cable.

Resolution refers to the number of dots produced per inch by the printer. Most portable printers offer a printing resolution of 300 dots per inch (dpi). This produces enough detail for excellent text and adequate graphics.

For higher resolution images, a few portable printers can produce 600x300 or 720x360 dpi output. This results in slightly better looking output, but does not match the true 600x600 resolution of most laser printers.

Manufacturers of thermal transfer and ink-jet printers now offer color ribbons/ink for color printing. By replacing the black ribbon or cartridge with a three color model, some printers can produce full-color output.

For ink-jet printers, color tends to be quite acceptable. You will find that color cartridges do not last very long, but portable models are acceptable for a few color pages.

Color with thermal transfer printers tends to be less useful. Most color ribbons have difficulty lasting even a full page. Even worse, color tends to be not professional enough for most businesses.

Thermal printers cannot print in color, since the paper controls the printing process.

For black and white printing, most portable models can print a maximum of four pages per minute. In practice, many print at closer to one page per minute. For color or more complicated graphics, some printers will require as long as 45 minutes to churn out a full-color image.

If you expect to print multiple pages at a time, you should pay extra attention to the sheet feeder and battery performance.

Sheet feeders can hold anywhere from 5 to 80 pages. They allow you to avoid the hassle of feeding paper manually one sheet at a time. When examining a feeder, make sure you can feed more than just full-sized sheets. The best feeders will also handle envelopes or transparencies.

The performance of the printer's battery also plays a critical role in the usability of the printer. Most printers use Nickel-Cadmium (NiCad) batteries. These batteries can print up to 90 pages, and can typically be recharged while still in the printer.

A few models use Nickel Metal Hydride (NiMH) batteries, which can print as many as 250 pages but take more time to recharge. In some cases, you may need to buy an external fast charger to effectively use an NiMH battery.

Portable printers tend to be fairly inexpensive. Models range from a low of $200 for non-color thermal transfer printers to a high of $350 for a color ink-jet model.

Since portable printers tend to use very small cartridges or ribbons, they cost more per page to print. You can expect to pay 5¢ per page for thermal transfer printers, and as much as 11¢ per page for some ink-jet printers. Color printer costs are even higher, hovering around 70¢ per page.

A car-lighter adapter, quick charger, and additional battery are all options you may need to purchase. Batteries can add $60-$80, while the car-lighter adapter and charger can easily add another $100.

Printing Without a Printer
There are alternatives to lugging around a portable printer. One of the best techniques for printing is to use a faxmodem with your notebook computer. If you need a page printed, you can usually fax it to a hotel's fax machine. Make sure to set the fax transmission on high quality, and try to send to a plain paper fax machine.

True Travel Size
Watch out for models that use an external paper feeder. These feeders can substantially add to the size and weight of the unit.