Every piece in the Epic Supply range is double-layer muslin cotton, nothing else. Muslin is cotton woven in an open, loose weave, so it's genuine cotton, not a synthetic blend hiding under a soft finish (see is muslin cotton or a synthetic fabric for the full picture). Each piece arrives pre-washed, so it already feels soft instead of stiff, and it keeps softening with every wash after that.
A standard cotton tee is woven tight and dense, while muslin's open weave makes the difference obvious the moment you hold both up to the light. Those same gaps in the weave explain why muslin breathes better than regular cotton, especially in hot, humid climates. Every piece is sewn with flat seams and finished with child-safe dyes, with no harsh finishes added.
Muslin creases easily, which is normal for this weave, not a flaw. Wash cold on a gentle cycle, tumble dry low or hang, and skip fabric softener and high heat so the weave stays open and keeps breathing. Sizes run roughly newborn to 4 years, Epic ships worldwide with tracked delivery, and unworn pieces can be returned within 30 days; if you want to see the fabric difference laid out side by side, Epic Supply muslin cotton vs mass-market baby clothing is a good place to start.