Rayon. SUPER ABSORBENT: 4 layers of premium material, high density inner layer and breathable waterproof PUL, will not leak or create odor. The soft material provides a comfortable environment for the puppy, and the upper absorbent material quickly absorbs pet urine, keeping the puppy dry all night. NON-SLIP BOTTOM - There is plenty of non-slip silicone on the bottom of the fabric. The leak-proof non-slip backing helps keep your floor dry while staying in place. REUSABLE & WASHABLE: Guaranteed absorbency, washable over 300 times, fully machine washable, reusable multiple times, no odor, can be put in the dryer. NOTE: Do not use fabric softener, bleach or dry clean these reusable urine pads. MULTI-PURPOSE - Reusable Extra Large - 72" x 72" Dog Potty Pet Training Pads, for kennels and crates for large dogs, training puppies to pee in playpens or helping incontinent elderly, as birthing pads and incontinence mattresses and pet waterproof floor mats. They are ideal for protecting carpets, wooden floors, furniture, sofas, car seats during travel