The average NewBee will have to try EVERYTHING else before believing it is true... But time will show you that for overal cleaness, humidity, and cost nothing beats plain old newspaper (yes the kind that probably gets delivered to you daily)
Paper towels can work. They tend to shift the towels all over the place though, so you would probably find your bp just laying on the floor with no substrate.
I recently moved so Ive been using the paper that was used to pack the boxes. Huge sheets, with nothing on them. Clean and simple. I also just started a job where they deliver newspapers daily...needless to say I packed my bookbag full and went home. Im planning a move again so when Im settled Ill be using aspen.
and the winner is: NEWSPAPER UNDER INDENTED KRAFT PAPER very absorbent easy to clean not messy like aspen and no risk of impaction. I have to admit I feel kind of stupid because I have been using the above for twenty years and just recently switched to aspen because I wanted a more "natural look". I got really worried after witnessing my snakes eat a lot of aspen with their meals. I realized that I should do what is better for my snakes and not what is better for my "natural look" so I switched back to my favorite substrate of all times: THE INDENTED KRAFT PAPER WITH NEWSPAPER COMBO.