How Do You Store Your Banknotes?

Giving this a bump to get some eyes on it.

From personal experience, I advise against using binders and pages. The pages tend to warp or at least bend slightly on the outer edge, even when the binder is stored flat. That leads to damaged banknotes.

Instead, I use PVC-free currency sleeves and boxes from Wizard Coin Supply. The thicker the sleeve, the better. For banknotes worth $4 or more, I use Supersafe Heavyweight Currency Sleeves, which are a combination 5 mil (front) and 10 mil (back) thick. Personally I wish they were 10 mil front and back. I keep cheaper notes in Supersafe Standard Weight sleeves, which are 5 mil thick front and back. All sleeves are stored upright in currency boxes, which are kept in a temperature and humidity-controlled environment. Don't pack the boxes tightly; make sure there's plenty of breathing space.

I buy sleeves in bulk. Brooklyn Gallery is another good source for sleeves and boxes, and may be even cheaper than Wizard. A lot of times it comes down to shipping, though, because Wizard has a flat-rate for orders of $50 or more. Just do the math and see which place is cheaper for what you're ordering, including shipping and sales tax where necessary.