Amazon.com: Foamma 5" x 24" x 26" High Density Upholstery Foam Padding, Thick-Custom Pillow, Chair, and Couch Cushion Replacement Foam, Craft Foam Upholstery Supplies, Foam Pad for Cushions and Seat Repair :
Amazon.com: FoamTouch Upholstery Cushion High Density Standard(Seat Replacement, Sheet, Foam Padding), 6'' L x 24'' W x 72'' H, 1 Count (Pack of 1) : Arts, Crafts & Sewing