Archival Safe Methods and Materials: Part 2 -The CHEMISTRY of it all. - By: Bill Harvey

This side of the coin deals with storing and protecting your valuable items in a manner the actually protects them. Let me give you an example of how NOT to do it. I quote from a nice lady -a curatorial expert actually- who helped with my Article on Fabric. She sez....

"And velvet, well, my opinion is still bad, bad, bad. Velvet and silver is a 500% Don't Do It.--you will have hundreds of etchings over the surface that look as if tiny worms had burrowed just beneath the surface--and they're not fixable. Saw it firsthand once, and it was amazing."

Imagine that -you work very hard to protect something you cherish -with velvet -soft luxurious velvet even -it's padded and tucked away safely and one of the very things you do to protect it -ends up ruining it!

So what to do to protect your collection -the way the museum professionals do -the guys with advanced degrees and who can spell CHEMISTRY with out getting help from SpellCheck every-dang-time? A little vocabulary might be a helpful way to start out.

ACETATE
A plastic that may be good (tri-acetate) or bad (di-acetate).

ACID-FREE
Means just that. But you also need to know about...

ACID MIGRATION
If something that contains no acid is stuck closely enough to something that does contain acid -the acid moves into the acid free thing. The moral here is to be careful of what you stick the valuable thing in to / on to / next to.

ACRYLIC
Good plastic for archival undertakings. Stiff, clear and chemically stable.

ALKALINE
The opposite of acid and probably a good thing. Unless it's a bad thing.

BUFFER
A unique sort of chemical thing that is the opposite of both acid and alkaline -it neutralizes -or 'buffers' both. (And if this confuses you -find yourself a chemistry teacher to s'pain it 'cause it don't make a lick of sense to me either.)

HYGROSCOPIC
A material capable of absorbing moisture from its surroundings. This can be good or bad. Desiccants are hygroscopic on purpose. Paper is hygroscopic to some degree -can't be helped- and as such, paper may come to be nourishing to fungi and mildew. BTW both hops and alcohol are hygroscopic and absorb water from places like your brain and the lining of your bladder, which makes it smaller. Don't need to discuss the later effect -but a dehydrated brain is a large part of what is called a 'hang-over.'

LIGNIN
A component of wood fiber that breaks down into acid. The good news is that most of the lignin is taken out of most paper -except newsprint. Archival safe materials are almost entirely "lignin free."

MYLAR and MELINEX
Trade names for an absolutely inert and absolutely vapor-proof plastic. It has archival value in protecting things from atmospheric nastynesses.

OUT-GAS
(Cool word! Has a scientific edge to it and is useful for insulting people who are too full of hot air.) This is the tendency for some things to slowly emit / out-gas various damaging gasses. For example, see.....

PLASTICIZERS
Stuff in plastic that makes it more flexible. Plasticizers tend to evaporate / 'volatilize' / 'out-gas.' All this means that some plastics emit 'goo' that can mess up the things you store in them. A discussion of the good plastics and the bad plastic would quickly degenerate into something very like a graduate level organic chemistry class so -for the time being- if it smells like a cheap new shower-curtain- you are smelling the evil plasticizers and this is a bad thing.)

POLY-----
Most plastics start with the word "poly" and go downhill from there. In general, the good plastics for protecting valuable things are polyester, polypropylene, and, acrylic. (They don't smell.)

Enough chemistry for the nonce. In Part 3, The METHODS, we get down to the actual HOW-TO of it all.

What are 'archival materials'? What about 'archival methods"? Is "acid -free" a good thing? Here is a How-To chemistry lesson to help you protect and preserve your collectibles and antiques:

Bill Harvey makes drawer and display cases for collectors and museums at Home-Museum.com.
He is also author of the Collector's HOW-TO series for dedicated collectors and hobbyists who wish to display and protect their very best stuff.