Canon’s range of all-in-ones is divided into two types, the PIXMA MP range for budding (P)hotographers and the PIXMA MX range for those who need fa(X). In most ways, they remain very similar, but the MX series, where the MX420 sits pretty much in the middle, has Automatic Document Feeders (ADFs) as well as fax.
The PIXMA MX420 looks very much like Canon’s other all-in-ones, with the chamfered surround and fold-in feed tray to its ADF helping to integrate the look of the whole machine. The ADF can take up to 30 sheets at a time.
The full-width control panel has a comparatively large, 62mm LCD screen and well laid out controls. These are simplified by the four, large, mode buttons to the right of the LCD and three soft keys underneath it, which take on context-sensitive functions. There’s a large numeric pad to the right, a trio of specific fax controls and then large copy and scan job buttons. A WiFi indicator is set in just over the front lip of the case.
There's only one paper feed tray on this machine, with no paper cassette sliding in from the front. Instead you load plain or photo paper in the rear tray and it feeds through to a hinge-down front tray, which opens when you start printing.
Just to the right of the output tray, in the curved edge of the front panel, is a flip-open cover revealing memory card slots, which include CompactFlash as well as SD and MemoryStick. Canon is one of the few printer makers which still includes a CompactFlash slot, we suspect to maintain compatibility with some of its high-end cameras. There's a PictBridge socket underneath the card slots and this can handle USB drives as well.
At the back are sockets for USB and 10/100 Ethernet, but wireless connection is likely to be the most common choice. You can set this up using WPS or by entering a passcode, and the whole process only takes a couple of minutes.
Canon provides its usual suite of support software and drivers for Windows and OS X are standard, with Linux support also available via download. The printer has just two cartridges, one black and the other tri-colour, and these clip into place in the head carrier, which needs a little persuasion to open its retaining clips.