December 02, 2007

When "acid free" isn't actually acid free: Can you trust archival supplies to be safe?

Photo by Joe Nangle

I've been having some trust issues lately.

There's a popular archival supplier whose products seem to be slipping in quality. Then they sent out an email with claims about CD longevity that were misleading at best, utterly false at worst.

This is a HUGE dilemma for me. If I can't trust the quality of their products, I can't recommend them to my readers. And I know people come here to find reliable information about supplies. (Note: The photo storage boxes for sale in the left column are NOT from this manufacturer.)

I'm digging and doing some research. I'll keep you posted about what I discover.

Anyhoo. When I started digging, I discovered Mark Welch's articles. Mark is a scrapbooker. He's also a skeptic. I like to think of him as The Skeptical Scrapbooker, but his pen name is actually the Scrapbook Critic.

How Reliable is the "Acid Free" Label?

Back in early 2006, Mark learned about pH pens for the first time. Test papers for acid content in the comfort of your own home? What a great idea!

Then he visited several craft and scrapbook stores to purchase one so he could test scrapbooking paper. Turns out, scrapbook stores don't actually sell pH testing pens. Interesting, wouldn't you say? So Mark made several purchases online.

In an odd twist, it turns out some of the pens didn't work at all. See Mark's articles (links below) for more details on why certain pens failed.

Way more shocking, however, was the discovery that some papers sold at scrapbooking stores and via home sales were, in fact, acidic. All of those had been clearly marked as acid free, buffered and/or lignin free. Yeowch!

Acid Free Is Not Enough

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.

Benefit of the Doubt

As for me, I am so obsessed with the independent Photographic Activity Test (PAT) that I've always given manufacturers the benefit of the doubt on the "acid free" label. I figured since it was so easy to test at home, a manufacturer would be crazy to pass something acidic as acid free.

Turns out, I was wrong.

Check out Mark's articles for more details -- including the names of manufacturers he no longer trusts:

[Mark's] conclusion is that scrapbookers should buy a pH pen and test each paper they use.

  • This is not especially cumbersome: it takes just seconds to distress the back of a page and mark it with a pH pen.
  • Scrupulous retailers should be willing to do this at the checkout stand while the customer watches.
  • It is not enough to test just one paper from a manufacturer, because paper composition and pH levels may change from one print run to the next.
  • Unfortunately, a pH pen will not indicate a problem if paper is currently pH neutral, yet contains materials (such as lignins) which will degrade into acids in the future.

Thinking about buying your own pen?
Check out the selection of pH pens at Amazon. And when you purchase anything from Amazon via that link (regardless of what it is) it's like leaving a tip for yours truly, without having to fork over any extra money.


Anonymous said...

I love my pH pen - but the frustrating thing is that it has been identifying items previously thought to be acid-free as, well, not acid-free. Specifically, it is identifying a huge roll of supposedly acid-free thick paper (for enclosing odd-sized documents) as acidic - the previous archivist bought this roll, and paid a pretty penny for it, but I am loathe to use it.

I've also noticed places like Staples identifying plastic covers as "acid-free" - I'm suspicious.

kevin driedger said...

I happened across your blog today and what a fine blog it is. My professional interests lean a little more in the library direction, but there is a lot of overlap. And my hat goes off to anyone who understands old photographic techniques. I look forward to browsing your earlier blog entries.

Sally J. said...

@Anon -- It's possible the roll of paper was acid free when originally purchased...but if it wasn't also lignin free it will revert to acidic. But take heart! Maybe it's your PH pen that's mistaken. I'd check it with a new pen before deciding to toss it.

@Kevin -- So glad you found the blog. Don't be a stranger!

Antinous said...

I've recently discovered that some drawings that I did about 20 years ago on archival, acid-free film are a disaster. My Galapagos Marine Iguana is now less orange than the film on which he's drawn. Bummer. If you don't live in a real city, the people at the art supply stores are non-experts, so I'm glad to know that there's a way to test.

I followed your comment about Rosie the Vietnamese Riveter over here from BoingBoing. This is a great blog.

Sally J. said...

Antinous, I'm not sure the pH pen works on film...I think it's designed only to work on paper. All kinds of plastic (including film) go through unpredictable changes over time. It's dicey.

FWIW, people in art supply stores are not necessarily up to date on preservation guidelines... regardless of the size of the city!

Glad you found me via my 15 nanoseconds of fame on BoingBoing. That Vietnamese Propaganda project was one of my favorite jobs in grad school.