I have read several comments on where to buy fleece for guinea pig bedding?

Some say hardware or fabric stores and someone posted a link to an article that mentioned fleece is actually 100% polyester -I have some baby blanks bought inexpensively at walmart that are soft, look like many fleece photos, and state 100% polyester-so my question is -is this the same fabric can I use them? I have also seen a white pad about an inch thick in pet stores for cats can that be sewn in and used to help absorb urine etc and then washed as one?