The question we hear most in the studio is whether merino is only for winter. It isn't. A merino baby layer is the one piece we'd keep on a child from the first cold March mornings until the November rain, because wool doesn't simply insulate: it regulates.

A merino fibre is crimped like a tiny spring. Thousands of those springs trap still air close to the skin, which keeps a baby warm in a pram on a windy day at the Elbe. When the sun comes out or you step into a heated tram, the same fibre absorbs moisture vapour, up to a third of its own weight, before it feels damp, and releases it to the air. Cotton holds sweat against the skin; merino moves it away.

Babies can't regulate their temperature well for the first months. A good base layer does part of that job for them.

Fibre diameter decides whether wool itches. Coarse wool above about 25 micron is stiff and prickles; our merino is 17.5 micron, finer than a human hair, and simply bends away from the skin. For very sensitive or eczema-prone skin we blend 30 % silk into our long-sleeve layer for a cooler, smoother feel.

Our layering rule for Hamburg weather: a merino sleeveless body as the base, a cotton or merino-silk long-sleeve on top, then whatever the weather needs. In summer, the merino body on its own. Wash it at 30 °C on the wool cycle, or just hang it on the line overnight: wool is naturally odour-resistant and often only needs airing.

"Organic cotton" on a swing tag can mean almost anything. Some garments contain five per cent organic fibre; others use organic cotton and then bleach and dye it with the same chemistry as everything else. That's why we certify our baby clothing to GOTS, the Global Organic Textile Standard, and why it's worth knowing what the label actually promises.

First, the grade. A garment labelled "organic" under GOTS must contain at least 95 % certified organic fibre; "made with organic" means at least 70 %. All our cotton pieces are in the first group. Second, the chain. GOTS doesn't stop at the farm: every spinner, knitter, dye house and sewing room has to be inspected every year. Azo dyes, formaldehyde, PVC prints and nickel in press studs are banned, and wastewater must be treated.

Third, people. GOTS includes social criteria based on the ILO conventions: no child labour, a living wage benchmark, safe working conditions and freedom of association.

How to check: a genuine GOTS label shows the logo, the grade ("organic" or "made with organic"), the name of the certification body and a licence number. You can look that number up in the public GOTS database. If a brand can't tell you its licence number, ask why.

Our envelope-neck bodysuits, sleepsuits, muslins and grow-with-me trousers carry it on the inside care label, printed, not woven, so there's no scratchy tag against a baby's neck.