Have you tried covering part of the screen with anything other than a damp cloth? That is good for a temporary bump in humidity but won't keep it where you want unless you put a new towel on the screen every few days.

A lot of people here cover most of their screen tops with acrylic, plastic wrap, or aluminum foil. Anything that acts as a vapor barrier will help to trap the humidity. I like to use 1/8" thick acrylic that I cut out to fit over my screens.

Alternatively, you could try switching substrates. Cypress mulch holds humidity a little better than paper towel.

Shoot for your humidity to be around 50-60% normally and 70% during shed cycles. You just need a little bump in the humidity, shouldn't be too hard if you cover up some of the screen top.

http://ball-pythons.net/forums/showt...tment-Tutorial Here is one method.