Muslin cotton is woven in an open, loose way, and the small gaps between threads are what make it breathable and light on a baby's skin. It moves with a wriggling baby instead of sitting stiff, and it gets softer with every wash. Every Epic piece is finished with flat seams that sit close to the skin instead of digging in, which is part of why parents describe muslin as gentle on sensitive skin. That word is about comfort, not medicine: soft, airy cotton simply has less to rub or scratch against skin.
Our clothes are double-layer muslin, pre-washed before they leave us so they arrive soft rather than stiff off the bolt, and finished with child-safe dyes instead of harsh finishes. At home, wash cold on a gentle cycle, skip the fabric softener, and either hang the pieces or tumble dry them on low heat. Because we already pre-wash everything, you don't strictly need to wash Epic clothes again before the first wear, though plenty of parents do it anyway out of habit, and washing new baby clothes before wearing them is a reasonable extra step either way. Expect some creasing along the way, since that's just how a loose weave behaves and not a flaw.
Sizes run roughly newborn to 4 years, so the fit stays close to a child's actual skin through most of the early years. Vanessa and Bob design every piece in Bali and test the fabric on their own kids before it becomes a product. If your baby has a diagnosed skin condition like eczema or a rash, talk to your paediatrician or dermatologist about which fabrics suit them; we can only speak to fit and comfort. We ship worldwide with tracked delivery and take unworn returns within 30 days if the fit or feel isn't right.