Cotton MATERIAL: Expertly filled with 95% feather, 5% down. Covered with a top quality, 100% Cotton fabric with 233 thread count. Down-proof stitching prevents feathers from poking out. HOW TO MEASURE: Pull tight along the outer seams of your sham, then measure the middle of your sham, from seam to seam - height and width - to find the correct insert needed. RECOMMENDATION: For best results, use a pillow insert larger than your sham to properly fill the corners and create a firm, fluffy appearance. We recommend placing our inserts in shams that are 1" to 2" smaller than the insert, depending on the sham's fabric—thicker fabrics need a 2" larger insert for fullness, while lighter fabrics need only 1" larger. USAGE AND CARE: Suitable for indoor use with all types of shams and covers. Fluff the pillow a few times before first use and as needed to achieve a full, plump look—this helps maintain its shape for years! MADE IN THE USA: Every product in the ComfyDown catalog is proudly made right here in the United States. Thank you for supporting American manufacturing! You will love the difference!