“Acid free, non-archival”
Translation: “Although this is acid-free, we still don’t recommend it for long term use, for one reason or another…”
Basically something can be ‘acid free’ without being ‘archival’, but it can’t be ‘archival’ without being ‘acid free’. I mean… for example… egg tempera is acid free, but unless perfectly done it’s not archival, so I wouldn’t use egg tempera for any long-term work.
Although most places equate the two terms, “Archival” is equal OR better than “Acid-free” basically… ‘archival’ implies pH neutral (or less) and ‘acid free’, in addition to whatever other characteristics intended for the long term life of the artwork.
For example, cotton rag or linen paper (IF it’s pH neutral) is considered ‘archival’, since cotton rag paper just naturally lasts a lot longer than wood pulp paper. Longer fibers, etc. Make sense?
One thing to keep in mind is that a lot of ‘acid free’ materials (AND a lot of archival ones) are buffered so the pH is actually MORE than 7.0 (so it’s basic). The idea is that it will neutralize the acid in say, backing papers or media… to a point… but, that base gets used up, the more acid it has to deal with. For example… if your tap water is a little on the acidic side, and you use it to do a watercolor?
*insert sizzling sound effects here*
That’s my understanding. And whatever the case, it’s still MUCH better to have “acid-free” than not — the real issue is about reliability comparisons between acidic materials, and pH-neutral ones.
-=- Jen “I need Pepto” Pixelscapes
http://www.Pixelscapes.com and http://www.BewareofArt.com
Edited to add this…
P.S.: Here’s another example of something that can be acid-free but not archival. Plenty of adhesives are acid-free, but they still may yellow, crack or flake with the passage of time. There’s no such thing as ‘archival masking tape’ for example, only ‘acid-free masking tape’. Note that this is true even if they CLAIM it’s archival. The only archival tape is gummed linen or gummed rice paper… the only archival paper is cotton, cotton rag, linen, etc.
Similarly you might find something like say, “Adhesive-backed acid free paper” or “Acid free paper” with patterns printed on it. The paper might be acid free. The adhesive or the ink, might not be. Insidious, no?
[This message has been edited by pixelscapes (edited October 05, 2000).]