100% Cotton. Set of 4 Pillows DOWN DREAMS FIRM KING PILLOW - We also offer the Medium Firm Version and recommend that you try each in a store before buying to confirm the firmness best for you. This high quality pillow keeps the signature dual chamber structure; however, it has a tad more down in the inner chamber, which is different from your average firm pillow. FIRMNESS LEVEL - Enjoy sleeping on a firm, supportive pillow that isn’t hard as rock with the Down Dreams Classic Firm Pillow. Experience the pillow that is featured in many properties at Hilton and Hamptons Inn. Size: King (20"x36") Dual Chamber design with Fill Content: Minimum 75 percent Grey Duck Down Outer Chamber, Grey Duck Feather Inner Chamber. MATERIALS - Fill Weight: 56.12 oz. Cover: 233 Thread Count, 100 percent Cotton Cambric Barrier Fiber. CONSTRUCTION - Down Dreams Fill: Inner Chamber - 87% Duck Feather, 13% Down; Outer Chamber 75% (minimum). Double Needle Stitched, Corded Edges. SHIPPING INFORMATION - Pillows are shipped compressed for ease of shipping. Please follow the instructions included with your order to fully recover the pillow for use. DOWN DREAMS FIRM KING PILLOW - We also offer the Medium Firm Version and recommend that you try each in a store before buying to confirm the firmness best for you. This high quality pillow keeps the signature dual chamber structure; however, it has a tad more down in the inner chamber, which is different from your average firm pillow. FIRMNESS LEVEL - Enjoy sleeping on a firm, supportive pillow that isn’t hard as rock with the Down Dreams Classic Firm Pillow. Experience the pillow that is featured in many properties at Hilton and Hamptons Inn and many other hotels. Size: King (20"x36") Dual Chamber design with Fill Content: Minimum 75 percent Grey Duck Down Outer Chamber, Grey Duck Feather Inner Chamber. MATERIALS - Fill Weight: 56.12 oz. Cover: 233 Thread Count, 100 percent Cotton Cambric Barrier Fiber. CONSTRUCTION - Down Dreams Fill: Inner Chamber - 87% Duck Feather, 13% Down; Outer Chamber 75% (minimum). Double Needle Stitched, Corded Edges. SHIPPING INFORMATION - Pillows are shipped compressed for ease of shipping. Please follow the instructions included with your order to fully recover the pillow for use.