Posted By:
Ryan ChristoffDaniel,
Personally, I think glue remaining on a card would be far more destructive than this mysterious water-retention alteration you've posited.
But a much more legitimate concern should be what will happen to the paper residing inside of a slab after 20 or 30 years? Although they are not air-tight, they are pretty close. Some of the sealed card condoms within slabs probably are airtight. Depending on the quality of paper, the acids that are released over time will destroy the card itself without air to dissolve into.
Anyone who has collected pulp magazines for more than 10 years has probably had the experience of witnessing fairly white pages become brittle and brown almost before their eyes.
Most baseball cards weren't made on such poor quality paper (maybe some strip cards) but still have acids in them that shouldn't be trapped inside an airtight environment.
Jim, since you have thousands of high-grade cards in slabs, care to speculate on what they might be like in 20 years? Do you plan to poke holes in the slabs to let some air in? Are you altering the cards by letting the acids destroy the integrity of the cards?
-Ryan