Apple's iOS 4.2 update for iPad, iPhone, and the iPod touch finally arrived this morning, and PCMag got a early look at the update, which enables AirPrint, Apple's wireless printing solution for the iPad.

The good news is: AirPrint is incredibly seamless. The bad news is: it currently only works with 10 printer models—all of them from HP. On December 27th, HP will release six more AirPrint-enabled printers. Apple claims the number of AirPrint-ready printers will increase down the road, as will the number of manufacturers.

Luckily, we had an AirPrint-enabled HP printer in the PCMag Labs on which to test the iPad's new feature. The process is simple: make sure both your iPad and the printer are connected to the same wireless network. If you want to print a document, there's an icon in the upper right-hand corner of your screen—tap it, and a pull-down menu of options appears. One of those options is to "print"—select it, and then your iPad searches for available printers. This search should take very little time, and the iPad then remembers the printer and doesn't need to search. In this same window, you can adjust the number of copies being printed, which obviously defaults to one. Once that's set, press "Print" and in a matter of seconds, your document will appear.

If you want to print a photo from your library, AirPrint is smart enough to know the difference between the photo and a document, and tells the printer to use the photo tray and paper (provided you've loaded the printer with photo paper). There's nothing extra you need to do—it automatically defaults to photo-printing mode when you decide to print an image. The process is identical to document printing—tap the icon, select the printer, and decide on a quantity, and you're set. Obviously, printing a high-res color photo takes a bit longer than a document, but the entire process for a postcard-sized photo took about a minute. The quality of the print is also impressive—an HD photo of the Golden Gate Bridge turned out crisp, though the color tones seemed different than those of the same image on the iPad's screen. These types of issues can be adjusted on the printer itself, however.

Apple also updated the iWork suite to include better fidelity support for Word docs upon import and export, and of course, printing was added as an option to each of the three iWork apps (Numbers, Pages, and Keynote). In these updated apps, when you select "Print", you get a print preview mode, where you can choose whether to print in portrait or landscape mode and how large to make the text and images appear on paper. There is also the ability to divide documents across more than one page, like a gate-fold, simply by moving a slider that enlarges the image while showing you a grid representing the location of the paper's edges.

Another nice touch—printer alerts will appear on your iPad. For instance, we got a notification on-screen that our printer was low on ink.

For more, check out PCMag's hands-on with AirPlay, Apple's wireless streaming feature that sends music, photos, and video from iOS devices to AppleTV, as well as our review of iOS 4.2.

And don't miss the slideshow above, and our video below.