It’s not often there’s a step change in the printing world. The introduction of both the first laser printer and the first inkjet qualify, and the combination of printer and scanner into the all-in-one is another example. What we have with the introduction of PageWide technology is one of the first consumer examples of a Holy Grail of inkjet printing.
HP’s Officejet Pro X551dw uses PageWide, a development of the EdgeLine tech available in high-end HP machines like the CM8050 multifunction and some of its commercial photo kiosk printers.
The basis of this is an inkjet print head that runs the full width of the paper it’s printing on. This single change in design makes a big difference to the way a PageWide printer works. No longer does the paper have to stop numerous times to wait for the print head to pass across it and print a strip of text or graphics. The paper can now move continuously with ink dots being fired from any or all jets, all the time.
Sit up and beg
The Officejet Pro X551dw is a big machine, bigger and taller than most desktop colour lasers, but with an unconventional design. The main print engine sits beside a 500-sheet paper tray, which has a peculiar bent plastic support above acting as the output tray. This support has an empty space under it - good for little other than a manual, or possibly a potted plant.
The printer’s output slot is covered by a powered flap, which lifts automatically when a print job starts. We assume this is to protect the print heads from dust. There’s a 50-sheet multi-purpose tray on the left-hand side, too, for feeding envelopes, special media or photo papers.
On top of the print engine is a 109mm LCD touchscreen, which is gesture-sensitive and gives access to HP’s ePrint Center print apps. Set into the side of the display’s support stalk is a socket for USB drives. There’s another at the back, though it’s hard to reach.
A flap in the front cover folds down for access to the ink cartridges, which, like the heads, are full width. They slide in and click into place very simply and, with capacities of between 2,500 pages (standard colour) and 9,200 pages (high-yield black), aren’t going to need replacing that often.
The head is a matrix of 10 smaller, overlapping head elements set in two banks. They overlap by 30 nozzles, so you never see white bands down a print and software takes care of the overlaps, so you don’t see denser banding either. The head is a lifetime component, so running costs are down to ink alone.
Connection can be via USB or 10/100 Ethernet, but a Wireless N connection is the most versatile, as the printer is fully compatible with HP’s ePrint Center and can be printed to remotely and via Wireless Direct - at least in principle.
HP’s headline speed for the HP Officejet Pro X551dw is 70ppm, but there are a couple of provisos. This is a page to page time, with no account taken of the time taken to rip the pages or for the printer to prepare itself. It also doesn’t use the ISO print set, which includes a range of text and graphics pages, in black and colour. HP quotes a speed of 42ppm for an ISO print.
The 70ppm is also in what HP variously calls General Office and draft mode, though this produces respectable prints that are just a little lighter than normal. On short print runs – and the average office document is still under five pages - the fast print is counterbalanced by up to 34 seconds of preparation time before the first sheet is fed (this was for our 80-sheet PDF file).
Our five-page black text document took 19 seconds to print in both draft and normal modes, with over 10 seconds of that taken up before the job started, rather swamping the speed of the actual print. This gives a real world speed of 15.8ppm, still impressive, but a bit more down to earth. Preparation time counts for less, proportionately, on the 20-sheet test and this completed in just under a minute, giving it a speed of 20.1ppm.
Duplex print is a standard feature, something that MemJet’s rival technology can’t yet match and the same 20-page document printed as a 10-page duplex job gave 17.1 sides per minute; very impressive. To give the printer its head, we also let it go on an 80-page mixed content PDF file, which produced an excellent 29.5ppm.
As for 15 x 10cm colour photo prints, fed from the multi-purpose tray, they took between 20 seconds and 30 seconds, which is also very fast. We couldn’t find any way to print these borderless, either from a PC or USB drive. We also had trouble printing from a Samsung Galaxy Mini Android phone, though we suspect this is an early glitch in the driver.
So, although you should keep the headline figure in perspective, this is a very fast machine, much faster than an equivalently priced colour laser. A 40ppm colour toner-based printer is likely to cost at least £700.
The print quality is also much better than you’ll see from a laser. Using pigmented inks throughout, black text is very much of laser quality, crisp and with no sign of jitters or jaggies. The lack of a moving head means there’s no possibility of misalignment between head passes.
Colours are bright and intense and registration of black text over coloured backgrounds is precise. Photo prints, whether on plain or photo paper, are detailed, with natural colours and the much larger gamut that only an inkjet can offer. In short, print quality is as good as we’ve seen from any four-colour inkjet machine.
If you’re considering buying a colour laser printer for office use, you really ought to consider the HP Officejet Pro X551dw. It’s likely to print more quickly – though it takes too long getting the first page out – and it’ll be considerably cheaper to run. Moreover, print quality, particularly if your typical mix includes photographic content, will be better than anything a laser can produce.
Manufacturer and model
HP Officejet Pro X551dw
ISO print speed black, colour (ppm)
Print resolution native, black enhanced, colour enhanced
600, 1,200, 2,400 x 1,200
1 x 500-sheet, 1 x 50-sheet
Maximum paper size
Pages per month max, typical
C, M, Y, K
Min ink drop size (pl)
Wireless, USB 2
Print without PC
Wireless Direct, ePrint, USB
Dimensions and weight (mm, kg)
517 x 399 x 414, 17.1