In that case it's left to me to say that aspen is BAD
I hate the stuff , it looks horrid , it makes light coloured snakes plus white or albino ones look washed out and it gets everywhere ( used to drive the wife bonkers ) as it seems to stick to the snakes when you get them out .
I use dark , rich looking orchid/ reptile bark looked great and natural ,
it makes the snakes look wonderful and colourful , holds as much or as little moisture as is needed and It can even be sieved / cleaned / dried and reused ( if you're on a tight budget ). .