Stamps Slightly Curl In Stockbook - Advice Needed, Or Explanation?

Hello to all, and a very good evening!

I'll dive right into why I am posting -

I collect MNH topical stamps only. The material is housed in Lighthouse brand stockbooks, with slipcases.

Everything is great, and I love collecting, except for one nagging problem!

When going through my stamps, they sometimes slightly curl in the pockets. This is most profound in the winter months, then flattens out in my air conditioned room in the spring and summer.

Is this normal? Its not too extreme, but I thought I would post this message. I read elsewhere that the gum on the back is the culprit.

Any advice? Or perhaps further explanation on why this happens?

Finally my most dreaded question - they are not ruinied are they? Like I said, its back and forth. I love my stamps, but this problem is driving me crazy.

Thanks in advance!

Greg

Sounds like the air in winter is too dry. Maybe a humidifier in the stamp room could correct that.

As to damage issues. Probably nothing in the short term.

Long term, maybe someone else can pipe in.