I bought this from a studio photographer's estate where it was stored in unknown conditions. For what it's worth, our local climate is dry and relatively cool.

I bought this box along with an identical box. I've been using the other box for paper negatives (see sample pic)—no problems so far, so it's a good bet the opened box is just fine. No guarantees, obviously.

Something to note: this is apparently a very high contrast paper, meant to print low contrast negatives. Using it for paper negatives has been fun and produces interesting results, but I'm not enough of a photographer to need another whole box.

Will be carefully packed and shipped promptly.