The Brother PocketJet PJ673-K is Brother's latest addition to its line of thermal mobile printers, a group that includes the Editor's Choice PocketJet 6 Plus PJ663-K See it at Amazon UK. Almost identical in some ways to the PocketJet 6 Plus, its key difference is that instead of offering Bluetooth as a potential connection choice for mobile devices, it offers Wi-Fi instead. However, the software support for Wi-Fi is limited, which means the most practical use for the printer may be as a portable device that you can connect to your laptop by USB cable.

Brother says that it sells all of its PocketJet printers, including the PocketJet 6 Plus, the Brother PocketJet 6 PJ662-K, and the PocketJet PJ673-K primarily for in-vehicle printing. You can use it in a delivery truck to print a receipt, for example, or in a police car to print a ticket. However, all three of the printers are also useful for office-centric road warriors. The PocketJet 6 Plus and the PocketJet PJ673-K are particularly useful in that role, because both offer 300 dot per inch (dpi) resolution, giving them better- looking output than the PocketJet 6, with just 203 by 200 dpi.

Note that Brother sells the printer by itself as the PocketJet PJ673 ($479 list), but it comes without an AC adaptor, a battery, drivers, or documentation. The PJ673-K version that I reviewed, adds all of that plus a soft carrying case, a USB cable, and 100 sheets of Brother's Premium thermal paper.

A Word About Paper

The mention of thermal printing may bring up images of old, low-end fax machines with paper rolls that print documents as tightly wound scrolls with a chemical odor. However, as I've pointed out in other reviews, that's not an absolute requirement for thermal printing. More important, it isn't true for any of the PocketJet models.

Brother offers several paper types and formats. For my tests, it provided letter-size Premium in a fanfold stack. The Premium paper, which has a 20-year archiveability rating, also comes in letter- and legal-size single sheets as well as roll and perforated roll formats. Other paper choices include Standard paper (with a 7-year rating) in rolls and perforated rolls, and Weatherproof (meaning water resistant) paper, with a 20-year rating, in roll format.

As you would expect, the cost per page varies with the type of paper. The price for the different choices falls between 7 and 26 cents per page at list price, but Brother says that street prices are often lower. The fanfold premium paper I tested with is $53.36 for 600 pages at list price, or 8.9 cents per page. The look and feel is similar to clay-coated inkjet paper, and there's no chemical smell.

Portability and Setup

Like the other PocketJet models, one of the PJ673-K's strengths is its portability. The printer weighs 1.1 pounds by itself, or 1 .3 pounds with its rechargeable battery, and it measures just 1.5 by 10.0 by 2.2 inches (HWD). That easily makes it light enough to carry around without a second thought. Brother says you can print about 70 pages on a fully charged NiMH battery (with additional batteries available for $39 list each), or 300 pages with the optional Li-ion battery ($155 list).

Initial setup consists of inserting the battery and plugging in the AC adaptor to let the battery charge. You can then install the driver on your computer to let you print over a USB connection, or download an app to your phone or tablet for printing over Wi-Fi. However, the only Wi-Fi mode the printer supports is ad hoc mode, which isn't available on all phones or tablets.

Unfortunately, OS support is limited, particularly for Wi-Fi. The PJ673-K comes with USB drivers for Windows 8, 7, Vista, and XP, and you can download apps for Wi-Fi for an iPhone or iPad. If you're so inclined, you can also download a software development kit (SDK) for creating your own Wi-Fi print apps for iOS. However, that's basically a tool for companies with both IT departments and a reason to buy lots of printers for a company-specific solution, like in-vehicle receipt printing. For typical road warriors, the SDK isn't of much interest, and might as well not exist.

Speed and Output Quality

I ran my tests using a USB connection and a Windows Vista system. Thanks to the fanfold paper, I was able to run our complete business applications suite, something I couldn't do with the PocketJet 6 or PocketJet 6 Plus, since I only had single sheets for manual feeding with those printers.

Brother rates the printer at 6 pages per minute (ppm). On our business applications suite (timed with a stopwatch in this case), it came out to 2.7 ppm on AC power and 1.7 ppm on battery power. As a point of reference, that makes it faster on AC power than the inkjet-based Canon Pixma iP100 Photo PrinterSEE IT, at 2.5 ppm.

The PocketJet PJ673-K's output is best described as surprisingly good for a thermal printer. Text quality is on a par with a typical inkjet, making it good enough for most business use, as long as the look and feel of the paper won't be an issue.

Graphics quality, similarly, is generally acceptable for internal business use, despite obvious dithering in the form of visible patterns. You may also run into problems with some graphics. In one case in my tests, thin lines in a line graphic with a dark background were completely filled in. Photo quality is good enough to print recognizable photos from Web pages but also shows obvious dithering.

I'd like the PocketJet PJ673-K a lot more if it offered Wi-Fi modes that would let it connect to a wider range of hardware and if Brother also provided apps for more phone and tablet operating systems. That said, if you're looking for a mobile printer to use with either your laptop or one of the few mobile devices that work with the PJ673-K, it won't matter that it doesn't work with other hardware.

The printer's speed and output quality is more than acceptable for printing emails and attachments when you need hard copy on the road. It also helps that the look and feel of the paper is appropriate for printing, say, a proposal or other material on the spot for a potential customer or client. In short, the Brother PocketJet PJ673-K is light enough to carry with you at all times, and it prints fast enough and well enough for many, if not most, purposes when you're on the go. If you don't need to print on plain paper, it's unquestionably a reasonable choice.