Most skins have enough oil remaining in them to avoid drying out, even tanned hides will remain supple for many years. The biggest issue is bugs.

Moth Crystals are a pain in the rear as well, their odor is less than pleasant, and when handling materials you can inadvertantly brush some in your eyes. I like incense cedar better, it has a pleasant odor which will keep you in good standing with your spouse. It repells bugs as well as moth crystals and you can buy thin slats (used for closet lining) from any hardware store - cut them to length and line the drawer bottoms with them.

Hitting them with a belt sander will restore the odor after you've used them for a year or more, so a small investment will last an awful long time.

As your material stash grows moth balls will become a larger issue, as you will be adding more to cover your new acquisitions - at some point you'll be banished to the garage.

KB