Muslin is a unique cotton fabric first introduced into England in the late 17th century. Muslin has a light, open weave that allows air to flow seamlessly through the material. The soft natural fibers allow your baby's body temperature to adjust naturally, eliminating over-heating, but ensuring warmth and comfort. aden + anais wraps will allow you to safely swaddle your baby, giving you confidence that your baby will experience a peaceful and secure sleep. These delicate cotton wraps are light, yet extremely durable, and can be machine washed and tumble-dried. Best of all, the more you wash aden + anais muslin wraps, the softer they get, as the air from drying creates a unique waffled effect in the fabric. Be sure to wash them before your first use. Other Uses Beyond Swaddling: As an open sheet On the floor for tummy time To shield you and your baby while nursing in public As a burp cloth Draped over your stroller to shade your baby As a summer time blanket Each packet includes 4 large unique cotton muslin wraps (47 inches x 47 inches) as shown.