How we test.... laser printers

Computer Shopper’s suite of print tests is designed to replicate real–world print jobs, from printing quick draft text documents through to business graphics and even photos.

The scores we print with each review give an overview of a printer’s performance and running costs, and are graphed against average figures we’ve obtained from the countless printers we’ve had through our lab. We also subject each laser to a wide range of quality tests. By the time a laser printer leaves our hands, we’ve studied more than 130 pages of plain paper output and at least 10 photographs.

To find out how quickly a laser produces high quality text, we print 50 copies of a formal letter at a suitable quality for correspondence. For lasers, this time is normally very similar to the Draft speed result (see below). We record the time between submitting the print job and when the last page has finished printing, but we also make a note of how long the first page takes to print.

We time how long it takes to print two 10x8" photographs on A4 paper using the highest available print quality settings, and how long three A4 pages each with two 6x4" photographs take to print.

All of our timed document tests are performed with the laser ready to print. Finally, we allow the printer to enter its power-saving mode, wait more than two hours and send a single copy of our formal letter, timing how long it takes to warm up and finish printing the document.

TESTS

Mono costs

SETTINGS: Manufacturer’s yield figures where available

WHAT IT DOES: This figure indicates how much you can expect each page of black text to cost, including VAT. We search the internet to find the lowest price for the manufacturer’s own branded toner. Wherever there is a choice we choose high-yield supplies, which cost more but print more pages, making them better value. If the printer has other consumables, we search for their lowest price too.

We find the manufacturer’s figures for how many pages each consumable will last. For toners, this is usually calculated using the ISO/IEC 19752 yield-testing methodology which uses a black text and graphics pattern that covers five percent of the page. We divide the cost of each consumable by how many pages it will last, adding the figures together to give a total cost per page in pence. Bear in mind that the cost of consumables fluctuates, so this cost may change slightly within a few months of our original review.

Colour costs

SETTINGS: Manufacturer’s yield figures where available, colour printers only

WHAT IT DOES: This figure indicates how much you can expect each page of colour text and graphics to cost, including VAT. We search the internet to find the lowest price for the manufacturer’s own branded colour toners. Wherever there is a choice we choose high-yield supplies, which cost more but print more pages, making them better value. If the printer has other consumables, we search for their lowest price too.

We find the manufacturer’s figures for how many pages each consumable will last when printing colour pages. We divide the cost of each consumable by how many pages it will last, adding the figures together to give a total cost per page in pence.

Our laser colour figures include cyan, magenta and yellow toner and the price of other consumables. Our colour cost figure is for 15 percent colour coverage per page: we publish a separate mono costs figure, so we don’t include black toner in the colour costs. Bear in mind that the cost of consumables fluctuates, so this price may change slightly within a few months of our original review.

Draft speed

SETTINGS: Draft text mode

WHAT IT DOES: This test is designed to show just how fast you can expect each printer to produce black text. We print an Acrobat PDF file that contains 50 A4 pages of Alice In Wonderland, timing from the moment we submit the print job until the last page has finished printing. We include the time taken for spooling, as some print drivers prepare the job quicker than others.

This test is conducted at a printer’s Draft setting, provided the results are solid and legible. Where this isn’t the case, we increase the print quality and repeat the test. If a printer has automatic duplex (double-sided) printing, we repeat the test in duplex mode

Print speed through the looking glass

Normal speed

SETTINGS: Default print quality

WHAT IT DOES: This test aims to show how quickly a printer can produce pages of text and graphics at a presentable quality. We print an Acrobat PDF file that contains 24 colour pages of mixed web content, PowerPoint slides and high-resolution magazine pages. We time from the moment the job is submitted until the last page has finished printing. We include the time taken for spooling, as some print drivers prepare the job quicker than others. The result is expressed as pages per minute.

This test is typically conducted at a printer’s default settings, provided the results are solid and free from excessive banding or other problems. Where this isn’t the case, we increase the print quality and repeat the test. Mono lasers print the document as greyscale pages.

A set of graphics-rich pages really tests a printer’s abilities.

Photo speed

SETTINGS: Maximum print quality, colour MFPs only

WHAT IT DOES: Not all colour lasers excel at photos, but some are very competent. We test each printer’s photo performance by printing six 6x4" photos onto three sheets of plain A4 paper.

We time the test, which is performed at the maximum available print quality. Any advanced options that improve print quality are turned on. The results are expressed as pictures per minute.

We examine the quality of the results with the naked eye and also under magnification.