how important (if at all) is it to you to use acid-free and/or lignin-free papers in your mache work? i ponder lately whether its worth the money to buy the usually more costly papers that have both of those qualities. i think with the effort involved everyone would like their work to last, but i see a lot of more 'high end' artists like stephen hansen use regular kraft paper and newsprint, neither of which is acid-free (so i'm pretty sure it's not lignin-free either). does the act of essentially 'encasing' the papers in a paste (many of which are acid-free themselves, like methyl cellulose and pva glues) already greatly extend the life of the paper itself? it seems to me that the longevity of, for example, a sheet of tissue paper by itself and a sheet of tissue paper that is completely coated in one of the aforementioned adhesives would be quite different. it doesn't seem like artists with expensive pieces would be using non-archival paper if it were that big of an issue in mache, but you never know. i also wonder if by removing lignin from the paper that is used in mache, it compromises the strength, as i think lignin is the material that makes the wood strong and firm.

what are your opinions on acid-free and lignin-free papers?  or have you heard anything about this subject but in context with mache?

thanks.