Saturday, March 21, 2009

Archival Storage: Acid-Free and More

preserve, protect, present with archival materials


You've seen these words on photo albums and scrapbook supplies, but I bet you didn't know that they are basically meaningless. Yep. That's right. Sad but true.

There is no standard legal definition for any of these terms. Which means that companies are free use these words to describe any product they want to sell - even products made from materials which are known to cause damage to photographs. I have personally seen those notoriously damaging sticky magnetic albums sold as archival. I nearly caused a scene in the scrapbook store. --Sally Jacobs, The Practical Archivist

The world of "archival" storage is complex; if you want to be sure the things you are saving will last through the years, let me point you to some good resources.

1. Guidance on storing almost anything: Saving Stuff, by Don Williams (senior conservator of the Smithsonian Institution) and Louise Jaggar)

Want to preserve photos, school papers, vintage books, textiles, fine art, macaroni/bean mosaic artwork - or almost anything else? This book will tell you what to do - how to protect your treasures from light, heat, mold, contaminants, and more.

When you're looking at photo albums, the key words (according to Don Williams) are acid free and no polyvinyl chloride. "Check that the plastic sleeves into which you slide the photos are made from polyethylene, polypropylene, or polyester rather than polyvinyl chloride."

2. Acid free and lignin free: The Practical Archivist

A good starting point would be her post When "acid free" isn't actually acid free: Can you trust archival supplies to be safe? Here Sally argues for testing all your supposedly acid-free paper (before you buy it, if possible) to be sure it really is.

She also states that acid free is insufficient. "Paper needs to be lignin free as well. Lignins are a by-product of the paper making process. It's the lignins that turn non-acidic paper to acidic. In other words, something that is acid free today will become acidic over time if the lignins have not been removed."

And here's some of her advice on boxes: "The type of box you choose is important. Don't forget the sniff test - if it stinks, don't put anything valuable in it. Unfortunately, that rules out most of the pretty looking shoebox-style boxes. Between the paper and the glue used to adhere it, you're looking at some awfully scary chemicals. Your best bet is to stick with an archival supplier like Metal Edge or Gaylord or Light Impressions. Those metal edges are not just for strength - they also make it possible to construct the box without using any adhesives."

3. Going beyond acid free and lignin free: buffered

The Northeast Document Conservation Center explains: "The term buffered refers to the process of adding a buffer (such as calcium carbonate) during manufacturing to neutralize acids as they form over time in the storage materials. ... While buffered paper enclosures are generally preferred to acid-free, some drawings and paintings on paper, blueprints, and some photographs may be damaged by the chemicals used as buffers. These should be stored in neutral (unbuffered), low-lignin enclosures if paper enclosures are used."

The American Institute for Conservation of Historic and Artistic Works says, "While buffered products are the best choice for many paper objects, unbuffered products should be used for photographs, wool, silk, and leather, which are somewhat acidic by nature."

And a library resource notes that, "The American National Standards Institute (ANSI) recommends non-buffered storage for color prints and negatives, and buffered storage materials for black and white prints and negatives."

4. More good reading

The Society of American Archivists wrote about preserving memorabilia from the last election in an article entitled Seven Tips to Preserve Your Piece of History. The tips have much wider applicability, though.

For more general advice, you can turn to the Library of Congress

5. Glossary

University Products provides a list of frequently used archival terms and what they mean. The library at the University of Illinois at Champagne-Urbana also has a helpful glossary.

[Image from Light Impressions]


Cynthia Friedlob said...

Great post, Jeri!

I've purchased photo and paper preservation supplies from Light Impressions and find their product selection and service to be excellent.

But the other resources you mentioned are wonderful, too, especially "Saving Stuff." I'd bet that even the most organized and clutter-free person has something special stashed away and this looks like the place to find out how to store it properly.

Thanks for your usual thorough research on a very useful topic!

Jeri Dansky said...

Thanks, Cynthia. This one took many hours of research, but I learned a lot along the way.

Saving Stuff is one of my critical reference books, sitting on that bookshelf that's (almost) within arm's reach as I type.

Heather said...

I used to work in an Archives, so I can say that your post is spot-on. You did a great job of explaining things and I learned some things I hadn't known, or never fully understood. I really appreciate your effort to spread the word about how to properly archive one's personal memorabilia.

Regarding item #2, you can test items to see if they're acid-free by using a pH testing pen, available from the suppliers you mentioned. You simply make a mark on the item to be tested: Purple indicates a pH of 7.0 or above; Yellow indicates pH below 6.5.

If you need archival safe paper (such as to photocopy important documents or to use to interleaf between items), Permalife meets all the requirements (acid-free, lignin-free, buffered), and has an expected lifespan of 300 years when stored properly (available from Gaylord).

Jeri Dansky said...

Wow, Heather - thanks so much for your kind words. And thanks for adding to the discussion.