Labs

Inkjet printers - A3 photo inkjets

The best way to test inkjet printers is to print documents and pictures that reflect what users would print both in the office and at home. Our tests range from draft text on plain paper to best-quality photos on specialist glossy paper.

Our overall aim is to establish the print quality, speed, total cost of ownership, value and the longevity of each printer's output to see how it compares with others.

Photo quality

These tests use manufacturers' best-quality photo paper. We print an A4 photomontage and a borderless 6 x 4in colour photo to assess skin tones, colour transitions and gamut. We also print a borderless 6 x 4in black-and-white photo, as monochrome performance can vary considerably.

Draft mode

Our draft test examines quality and speed of text printed on plain paper. We print ten copies of a standard 5 per cent coverage A4 letter, as developed by IDC Consulting. We look for spidering around the edges of characters that should have a sharp outline: the ink appears to bleed onto the paper.

Standing mode

We use two tests for standard mode, both on plain paper. We print ten copies of the 5 per cent letter to assess quality and speed. The second test involves printing a single-page map from www.streetmap.co.uk

Presentation graphics

When you want to produce good photographs without the cost or thickness of glossy photo paper, plain paper won't do. For this, we use coated inkjet paper. We print our mono quality test, which determines the image quality of a greyscale file with black-and-white photos, fades and varying font sizes of text.

Fade resistance

Instead of conducting our own longevity tests for this Labs, we use Henry Wilhelm's figures. Wilhelm (www.wilhelm-research.com) is an independent research company, which uses accelerated fading to predict print permanence. The figures you'll find on the feature table represent the years of display before noticeable fading, changes in colour balance and/or staining occurs.

Wilhelm uses the industry-standard scenario where photos are placed behind glass frame in a home and exposed to daylight (450lux) for 12 hours per day. The accelerated testing is carried out at 35klux with glass-filtered cool white fluorescent illumination.

Printers not intended by manufacturers for printing photos (such as the Dell 720 and Lexmark Z735) aren't rated for fade resistance, so are best suited to those who won't need to print photos.

Do bear in mind that, although photos from some printers will last considerably longer than others, you still need to store them in a relatively airtight place. Air pollutants will degrade colours far quicker than light, so keeping photos in a frame or album will ensure they last longer.

How we work out the ratings

At the bottom of each review, you'll see six star ratings. They're calculated using a complex mixture of benchmark results, objective scores and subjective quality ratings. For full details on how we calculate the Running Costs rating.

Quality

The Quality score is based on the ratings given by a panel of judges to the prints from each printer. All prints are judged 'blind': the judges have no idea which printer printed the images, as the name is written on the back of each print.

We assess quality both under fluorescent lighting (for text and colour graphics prints) and natural daylight for all photos and the mono-quality print. We weight each of the quality tests differently, with the photomontage gaining the highest importance. Text quality is important too, although draft quality is less important since this mode is mainly about speed.

Speed

Print speed can't be ignored, and a printer that offers equal quality to another but delivers prints quicker is naturally a better choice. However, we haven't given speed as high a weighting as quality in the Value for Money rating, since most people would rather wait a bit longer for a higher quality photo.

We time from the moment the paper is picked from the input tray to the moment the last page is dropped onto the output tray. This eliminates any processing time introduced by our test rig and purely tests the engine speed of each printer. The results are shown in the graphs on the right.

FEATURES

We award points for many aspects of each printer. These range from warranty to OS support and driver options, and cover all physical attributes such as paper handling, connectivity and any TFT displays. Points are also awarded for the ability to print on CDs/DVDs and optional interfaces such as networking and Bluetooth. Lastly, we give points based on Wilhelm's fade resistance figures.

Value for money

The Value for Money rating is a weighted average of the Quality, Speed, Features and Running Costs ratings. We then factor in how much each printer costs (including delivery) to give a bang-per-buck result.

Bear in mind that the Value for Money rating is specific to each group of printers, so you can't compare the value of an entry-level inkjet to a premium photo printer, or the value of a mid-range model to an A3 printer.

Overall

The Overall score is a straight average of the Quality, Speed, Features, Running Costs and Value for Money ratings.