Topps 67 Baseball w/ Discolored Backs

[BranchRickey56]

Good Ideas and thoughts, Steve.

Your suggestion that the fading could be caused by acidic reaction from the boxes the cards were stored in makes sense, but only if the faded cards were touching the box cardboard. There seem to be way too many cards affected for that to be the main cause; perhaps 20% of my set of (so far) 544 shows some sort of color problem.

Steve, could discoloration be caused by touching other cards in storage, rather than touching the box? In other words, could you see an acidic reaction/discoloration caused by another card touching a given card, or by cards touching each other?

Also, I have over 500 cards from the 1965 BB set, almost none of which show this amount of browning. Does anyone have cards with this discoloration from the '68 or '69 sets? (As I mentioned, my cards from those sets were "borrowed" by the movers, so I don't have examples for comparison.)

I don't know anything about cardboard and how it's made, so your idea that Topps used different kinds of cardboard in different years is intriguing. Is there evidence that they may have done this or do you just think they might have based on what you've seen?

Again, thanks for the feedback and great ideas!