[DonVoigt]

Store them at 70 degrees F and 50% humidity.

The wood for the grips was "cured" before use, and was dimensionally stable. Most all the grips I have are still just fine, and not shrunk.

What some see as "shrunken" grips may be replacements that don't fit the frame fully.
Grease or oil soaked grips may have other problems.

I'd treat the wood like I would any other piece of wood that I was gong to use; everyone has a "secret recipe" or method they think is good or best. There have been a number of threads on this subject. maybe you can do a search and find them?

If you are collecting not shooting, see my first comment.

Welcome to the forum.