You’ll have heard it before. Keep your prints out of direct sunlight. Every piece of advice you’ll ever read about photo preservation includes the line. For those without the knowledge of why photodegradation happens, you may be tempted to throw caution to the wind and hang your prints wherever you feel based on the thinking of – what’s the worst that can happen.
The worst that happens to prints exposed to direct sunlight is photodegradation. It happens when the pigments and dyes absorb the high energy levels of UV rays from sunlight.
UV rays from the sun cause a chemical reaction in inks and pigments. Photodegradation happens when the chemical molecules begin to break down. The pigments that make up inks and dyes lose their colour.
Not only that but the paper that the prints are printed on can also be affected. Especially standard paper, which has no treatment at all to help the paper absorb the inks.
If you’ve ever framed a newspaper clipping, you’ll have seen first-hand the degradation that happens. Newspaper is the flimsiest material that will wrinkle, crease and yellow due to the acid content in the paper. Expose it to sunlight, the degradation happens faster.
Photo paper is acid-free. Standard paper is not. As paper degrades through age, it turns yellow and that happens because paper becomes more acidic with age. The problem with paper is the lignin content. You can get acid-free paper, and card stock that still contains lignin. Those papers and cards will eventually become acidic too. Those two types of paper are made from wood pulp and the quality you get depends on the treatment the manufacturer applied to the pulp.
- Acid-free paper has gone through a treatment process to remove pulp and is manufactured to last at least 100 years.
- Lignin-free only has the lignin removed. Not all acids. This paper just lasts longer than standard paper before degradation happens.
- Archival quality paper is made of cotton pulp rather than wood pulp ensuring there are no acids in the paper.
Now, you’d be forgiven for thinking that if your prints are on archival quality paper, that’s it. You can display it wherever you feel like because there’s nothing that can become acidic that would make the paper brittle.
Archival will only be archival quality when the inks and dyes used are of similar quality.
When framing for photo preservation, the inks and dyes are only as UV resistant as the material they are printed on. They are not immune to the dangers of sunlight. Even with UV-resistant glazing, they only offer a barrier.
The more protection you can put between prints and sunlight, the longer they will last. For maximum protection, the only solution is to keep the prints out of direct sunlight.
Archival paper combined with archival inks achieves the best photo preservation possible. The frame is the final piece of the puzzle that protects prints from environmental conditions such as dust, and debris.
Of course, for the print to be fully protected it ought to be printed and framed to a professional standard, which requires all the components in the frame to be acidic-free, including the picture mount and backing board.