We have recently added waterproof Dartex and Stretch-4 slipcovers for convenient ordering through our online store. They are designed to snugly fit 16" x 18" x 2" or 16" x 18" x 2.5" cushions. If you would like to order a different size, a different fabric, or would prefer to order fabric by the yard or roll, please contact our customer service department. We will add more options to the online store as customer demand necessitates it.