Rehardening Leather

[biker55]

Hi all, just finished a cell phone case and due to some overmanipulation the leather seems to have soften up some. is there a way to reharden the leather so that it retains it's shape better? don't know what type of leather I'm using since I purchased it from a local hobby shop. thanks

[Tree Reaper]

I usually wet it and then bake it in the oven but there's a fine line between hardening and ruining.

Lowest temperature for twenty to thirty minutes max.