Hey, welcome aboard! And congratulations on your new pair of snakes. It's so nice to have another member keeping Trans Pecos- & we look forward to you sharing your experiences here- I hope you love them as much as I do. So many people are convinced that all rat snakes are feisty, difficult pets- it's so not true, & nowhere is that more obvious than with "subocs" (as they're nicknamed). Are your snakes hatchlings? Or older ones?
Substrate- I still do the same thing- one layer of paper towels (makes clean up much easier), then a mix of shredded paper & some Carefresh (about an inch deep altogether). Great absorption, & keeps humidity lower. And yes, shredded clean paper is free & easy to come by.
BTW, please do start a new thread to share your new Trans Pecos.