Step 7: Step 7: Cut a piece of material.
Last step! Just cut a small piece of fabric (I used suede sherpa) and insert it into your new pet carrier backpack! I did not attach mine because rats tend to pee on everything to mark their territory and I wanted to be able to take it out to wash it.
NOTE: Make sure you get any left over materials of "fuzz" out of the purse/backpack so your pet doesn't ingest it.