Print longevity


HP photo inks are based on soluble dyes. Unlike pigment-based Ultrachrome and Durabrite inks produced by Epson for a sub-set of its printer models, dye-based inks are vulnerable to gas-borne chemical attack by ozone and other gaseous pollutants, plus the effects of naturally occurring ultra-violet (UV) radiation in sunlight and some artificial light sources.

So, on face value, HP Photosmart photo prints should be just as vulnerable to environmental fading factors as those produced by other dye-based ink-jet printers from rivals Lexmark, Canon and Epson. But HP claims otherwise and here's why. HP photo media is different to typical Canon and Epson photo papers. HP's print head lays down more ink than its rivals and the ink is absorbed into a 'swellable' gelatine-like layer that makes up the surface coating of the paper. Once the ink has dried, the dye is locked into the layer and protected from the atmosphere. Epson's ColorLife paper works on a similar principle.

All HP's longevity claims for its Photosmart photo prints is based on resistance to gas fading. HP states: "Up to 73 years, based on Wilhelm Imaging Research, Inc. using the HP 58 Photo Inkjet print cartridge and HP 59 Gray Photo Inkjet print cartridge on HP Premium Plus Photo papers"

Wilhelm figures are authoritative, but need to be carefully interpreted. HP's ink and media scientists confirmed to me that their photo prints bore no more resistance to UV fading than any rival dye-based ink-jet photo print. If you leave a dye-based photo print in a position that gets several hours of direct sunlight, your print will fade in weeks. Even indirect illumination, from sunlight reflected off walls, for example, is harmful. But with the use of UV-filtering glass in picture frames or by storing your photos in a dark place, prints should last well.