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I agree with this advice. One by one. I did a 98 Bowman Chrome and some Ultra as well and did a couple thousand cards with no damage. You have to have time though cause it takes hours.I had this happen with a 1997 Ultra platinum medallion set. The best way I found was to pull one cards apart at a time. Freezing didn't work, steam didn't work, heating in the sun didn't work, but one at a time left minimal to no damage.
Basically, any glossy or UV coated cards from the '90s until present will do it. And not just sets, but cards in packs too.
I recently found an unopened wax (cello) box of '94 Topps cards at a thrift store. When I got home and opened them, most of the cards in the packs were fused together, and I damaged many of them separating them one by one.
Like you, I keep my sets in binders so I don't have the problem. But I would think there are tons of people on this board who have sets from the '90s and '00s in boxes with no idea that the cards are now stuck together.