Organic and breathable where it matters most.™ Materials, Weight & Dimensions SafeSleep™ Cover Materials Print Cover: Organic Jersey Cotton, Non-Toxic Polyester Fill, Polyester Breathe-Thru Twill, Zinc, Easy-Close Nylon Zipper, 3D SafeSleep Technology™   Care Instructions & Certifications Care Instructions Print: Unzip and remove cover. Machine wash alone on gentle cycle with gentle detergent. Do not use bleach, stain removers, or fabric softeners. Dry alone on low heat. No dryer sheets needed for your print covers. Just like your favorite T-shirt, your print cover gets softer with each wash and the benefits of your cover get re-invigorated!  Certifications Nook Mattress Wrap in Nook Print Dozing Dots