I recently dug out my old collection, mostly comprised of hundreds of Spidermans. Unfortunately I neglected to ever change out the bags and, though the actual physical condition of the books are excellent, there is noticable
acid damage on the inside pages in the form of ink transfer as well as tanning. I suppose they could be classified as "off-white" but possibly even slightly darker. It hurts a little since I do still have a certain emotional investment
in these books, but I was also wondering about their actual value and how this might affect that. Any thoughts?
On a side-note I am now transferring all of them into new mylar bags with acid free boards and new boxes as well. About 30 years late mind you but there you go.