Allan Ong

Thanks! I was beginning to wonder why they started to discolor like that.

I have 5 coins -- 4 Presidential Dollar proofs (2 PF69, 1 67, 1 66) and a 2010 Cent (PF69) that are starting to show some discoloration similar to the kind a Sac Dollar would experience while in circulation. I've always thought the slabs are airtight... Has anyone else experienced this before?

The coins were slabbed earlier this year. It's unlikely that it's the way they came in the proof set as discoloration that's painfully obvious isn't likely to grade 69 UC!

just make sure you don't try to spend it!! you'd get quite a few funny (and possibly angry) looks if you did...