Colour laser printers
IntroductionColour printing has enjoyed a massive boost in the past three years, due largely to falling prices and new technologies. High-end colour laser printers have moved to a single-path design, meaning the paper is printed on in one go, rather than going around the printer four times picking up a different colour each time. Single pass is faster and is getting closer to mono printer speeds - essential for businesses that demand speed as well as colour. This new technology has overtaken the multi-pass technology of old, but multi-pass technology hasn't disappeared. It has been given a new lease of life in ultra-cheap colour printers. When you pay four or five hundred pounds for a colour laser printer, the amazing thing is that you have a colour printer at all; the fact that it only prints three or four pages a minute isn't such a worry. We've tested three new printers that bring high-end single-pass performance to a new mid-range level, squeezing the multi-pass models even further down towards the consumer level. Remember that printers with these capabilities were three or four times the price a couple of years ago. This range of printers is ushering a new era of colour printing - an era where buying a mono printer is looking more like buying a mono TV; there are now very few excuses to use one. The three printers are all laser-class printers, by which I mean they work as you would expect a laser printer to work - but the technology can and does differ. The HP LaserJet 3700dtn is a single-pass laser printer. The Xerox Phaser 8400 is a solid-ink printer, which is technically also a single-pass technology. The OKI C5300 is an LED printer - single-pass technology very similar to laser. Each technology has its strengths, though the results are closer than ever. Solid-ink technology
The Phaser 8400 uses a solid-ink engine, a technology initially developed by Tektronix that was bought by Xerox some years ago. Solid-ink printers use coloured wax blocks as ink. These are easy and clean to handle, unlike toner, and are melted down and sprayed through nozzles in a similar way to inkjet printing. Unlike an inkjet, though, the ink is sprayed onto a transfer roller, which transfers the ink to the paper. The solid-ink technology was always a bit unusual mainly because Tektronix held the patent and nobody else could make solid-ink printers. It had advantages over laser in the early days because the process is a single-pass one, which made it a quicker printer. Once lasers became single-pass, solid-ink had lost its edge and didn't fare too well against the more familiar technologies. Solid-ink still retains advantages over laser printers. Because the wax-based ink sits on top of the paper, you can get glossy results even on poor-quality laser paper. A criticism of early solid-ink printers was that the wax was laid-on too thickly and would even crack when the paper was folded. Tektronix and Xerox have long since solved that problem and modern solid-ink printers use a much thinner layer of ink. Now the pages are foldable and much more laser-like in their looks. The only thing that would distinguish a solid-ink print is its dithered tones. It's barely noticeable, but close inspection will show dots in gradations. Lasers also have their characteristics: there tends to be horizontal and vertical banding visible on parts of laser output. A year or so ago Xerox realised that solid-ink printers could no longer command a premium price, and re-pitched them to the lower end of the market. The latest model, while using the same technology, is still at the very bottom of the price bracket for mid-range colour printers, but performs much better than the cheap multi-pass laser models. Speed matters
In our tests, the 8400 showed that it could easily reach the claimed 24 pages per minute (ppm) on both mono text and full colour pages. However, this was using the fast colour mode. This is like a draft mode, though the quality is much better than with previous printers. The only difference is that the pages are lighter, so black text is a bit grey, and colour is a bit washed-out. They're quite usable for internal documents, but if you wanted to impress somebody you should use the default Enhanced mode. This takes the performance down to 12ppm, but the results are much more impressive. First page to print is always an issue for designers because complex PostScript documents can tie-up a printer's processor in ways that word-processing documents can only dream of. Our much-feared printer killer test is a worst-case scenario, being a document that uses complex vector graphics, though the file size remains small. The 8400 got our first page out in around 40 seconds, which would have been record-breaking a couple of years ago, and is still very impressive. Mono text pages took just eight seconds from mouse click to dropping onto the paper tray. These tests were done from a fully warmed printer. There is a standby mode that saves power by letting the ink cool; starting from this mode is a lot slower. The price of the 8400 starts at just £699 for the USB version, and £909 for the network version. Normally we don't look at non-networkable laser-class printers because having an expensive printer used by only one machine doesn't make much sense. However, now prices have dropped so low there's a good case for a single-user colour laser. Comparing the performance with cheap multi-pass lasers, the Phaser 8400 beats the pants off the competition - the extra £150 or so is well worth spending. Compared to more-expensive printers the 8400 still looks like a good deal. The style of output is worth checking out before you make the decision, so get some test prints done if you can. But for the price it's difficult to beat it. The HP LaserJet 3700 is a traditional colour laser printer, and its single-pass design means it can crank-out 16ppm in colour and monochrome. The price is a little more than the Phaser, with the USB only model coming in at £1,099 and the Ethernet version at £1,349 excluding VAT. If you were to compare the output with the Phaser, it would be on a par with the default Enhanced mode. Although the top speed of 24ppm is possible on the Phaser, that's at a lower quality than the LaserJet. Engine speed
There is also a cheaper LaserJet 3500, which looks much the same but runs a 12ppm engine. The price is similar to that of the Phaser, and would probably be a better comparison to that printer, as pages-per-minute speeds are the same. While the quality would be comparable, the first page out speed would be slower on the LaserJet. The engine speed is superior to the Xerox model, but the processing power lags behind a little. This means that the first-page-out times are slower. However, the slowest time for the Printer Killer page was 58 seconds - just 18 seconds behind the Xerox model. Even if you're in a hurry, 18 seconds won't kill you. The final printer we looked at was the OKI C5300n. This printer uses an LED engine, which in theory is as good as a laser engine; at least I've seen LED printers print as well as lasers. Unfortunately this time the quality was noticeably lacking. Compared to the HP and the Xerox models, the OKI fell down on a number of counts. The fine lines in the Printer Killer test image, black over colour, showed white edges that shouldn't be there. This is a registration problem that I've seen before, but I thought LED engines had improved enough to eliminate this effect. The poor registration may also be the reason for the vertical banding that also mars the image. While the image flaws may sound serious, and would probably put off graphics users, business customers are less demanding. Where accuracy is less crucial, the images are still far better than mono prints. And there's something else to recommend this printer to business users: it is fast at printing mono pages. While colour pages are printed at 12ppm, mono pages print at 20ppm. First-page-out times also lagged behind, with the colour page taking a minute and a half - three times longer than the Xerox. This, combined with the quality issues, makes the OKI less of a great deal compared to the other printers.