Which substrate for glass enclosures

I'm using carpet which I'm sensing is gonna get me edumacated in a minute...

I am using eco-earth (coco fiber) in my tanks now. It's nice for holding in/helping with humidity better at shed time. During sheds, I cover most of the screen top with cellophane (wetted to help it stick to the lid) and it helps raise it to where I want it. Tanks can be hard to "insulate," and mine is inside a shelving unit with rubebr feet to allow the UTH to be under it.

My ball is on cypress my corn is on aspen

I use reptibark and cypress mulch together. I feel like the cypress holds humidity a little better, but personally like the bark as well becuase its more compact and doesn't mold up. (I've had the cypress mold up around the water dish before. Gotta keep an eye on that. Don't want respitory problems)