Most rough fabric comes down to how tightly it's woven and what's been added to it. A tight weave leaves less give, so fibers rub against skin with every movement. Stiff finishes and rough seams make it worse, especially on a baby who can't tell you it's bothering them. Muslin avoids most of this by nature: it's cotton woven in an open, loose weave, so the fabric has give and doesn't rub against skin the way a tight weave does. That open weave is also why muslin breathes well and dries quickly, and why it creases so easily, which is normal and not a sign of poor quality.
Our clothes are made from double-layer muslin cotton and pre-washed before they ship, so they arrive soft instead of stiff off the shelf. We sew with flat seams to cut down on rubbing at the edges, and finish everything with child-safe dyes instead of harsh treatments. If you want to know why we recommend washing new baby clothes before the first wear, that's a good next read. For care, wash cold on a gentle cycle, tumble dry low or hang to dry, and skip fabric softener and high heat, since both can stiffen the weave back up; here's more on how muslin holds up in the dryer.
Softness also builds over time. Muslin keeps softening with every wash, so a piece that felt fine on day one often feels even better after a month of regular use. If your baby has a diagnosed skin condition, such as eczema, or shows ongoing redness or irritation, check with your doctor or paediatrician, since fabric choice can support comfort but isn't a treatment. Our sizes run roughly newborn to 4 years, and we ship worldwide with tracked delivery.