This Rainbow Fitted Crib Sheet from cloud island is suitable for standard cribs and toddler beds. Made from 100% cotton, this standard crib sheet fits a six-inch mattress and is designed with an all-around elastic for a secure fit over the crib mattress. Its adorned with tiny rainbow prints in soft colors all over a white background to give your nursery decor a cheery update. cloud island: Designed with love. Made without compromise.