Most people use news paper to save money. But news paper ink can be toxic and stain the skin on your snakes. I've seen beautiful snakes start looking dull after shed due to newspapers. Have you ever read a newspaper for like 15-20 minutes? Look at your hands after. That black ink stains your hands. Paper towel is good but can be pricy and doesn't hold up on humidity unless you lightly spray towels from time to time. Reptile bark or Cypress mulch is great but pricy. And it holds up on humidity. Aspen bedding gets moldy too fast when spills occur and substrate dampens. I've personally decided to go another route. I purchased a 60.6 L giant bag of "Planet Petco Aspen soft wood shavings" (oil free!!) for $14.99. It's natural and smells really good. Snakes love to hide and burrow in it. Most importantly, it absorbs fecal matter and urine for easy spot cleaning. My tubs are always fresh and clean. And my snakes are happy and love it. I had purchased the substrate last month and still have about 80% of a bag left. I spot check everyday, scoop out soiled areas when necessary, and then add a handful more in the tub. And once a month I completely change out all the substrate and disinfect my tubs. Snakes are healthy and it saves you time and money on always changing substrate and cleaning tanks constantly. In addition, I soak all my snakes twice a month in shed ease to help sooth and moisturize skin. So far I've never had a shedding problem. All snakes have had healthy full sheds. No retained eye caps or any other problems for that matter.