well just to preface i did say who knows because a lot of variables that can effect things like storage preservation which was mentioned above. usually things yellow due to light and can deteriorate do to things like moisture and handling. the oil on your skin/fingers can cause things to be opaque or turn translucent when handled. they smear. its possible of course but usually paper doesnt hold up well. im not a paper expert or archivist but i didnt think i needed to be in order to have that common opinion. in the end though who knows but it does make me very unsure and untrusting though it seems like he has a good reputation so maybe.