Our shelter actually has the sizes and instructions on their website. Check to see if your local shelter does too. Having worked at a vet clinic I know that they use pretty much anything. Old comforters for the larger dog kennels, flannel blankets/quilts, bath size towels, fleece blankets. However, the vet clinic that I worked at could afford to buy their own bedding for the kennels or the employees donated their cast offs. These blankets and towels get washed a LOT and it certainly wouldn't be necessary to go to great lengths to make them pretty (ie: quilted). The washers and dryers are crammed full and harsh cleaning products are used. Dogs will chew them as well as all kinds of body fluids wind up on them. I would feel better about donating to a shelter who tend to have less monies to buy the things they need.