I agree with Sandy. I would definately be concerned about whether or not the cardboard is acid free or not. I found this on a website
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"Chipboard Aka book board, I can only describe it as thick card board like the stuff your cereal boxes are made of but thicker. You can totally use your cereal boxes (although they're not acid free) to make your mini album. It may be a little flimsy but you can get away with it if the album is small enough otherwise go for something a little thicker. You can find good quality chipboard that is thicker at all good craft stores and scrapbooking stores."
HTH!