Substrate drying

[Inarikins]

I've kind of poked around for the answer (and I know it's here somewhere but I don't remember where I've seen it) but don't seem to have found the right search terms, so I was wondering. How do you bake your substrate so you don't have too much humidity when you put it in the tub?

[The Serpent Merchant]

Put it on a cookie sheet in the oven @ 250-275 degrees until desired dryness is reached.