What Cotton Jersey Actually Is — And Why 96/4

Almost every piece of underwear you own is described by a fibre — cotton, modal, silk. That is only half the information. How the fibre is turned into fabric matters just as much, and for underwear the answer is nearly always jersey.

Jersey is a knit, not a weave

Woven fabric is two sets of yarn crossing at right angles — shirting, denim, canvas. It is stable and it does not stretch much.

Jersey is knitted: one continuous yarn looped through itself, row after row. Those loops can open and close, which is why a knit stretches and recovers while a weave does not. It is the same structure as a T-shirt, and it is the reason underwear can follow a body instead of sitting on top of it.

Two jerseys show up in what we make:

• Smooth jersey — flat on the face, quiet under clothes, the one that disappears under a T-shirt.
• Ribbed jersey — alternating raised and recessed columns. It has more give across the body, more recovery, and enough weight that it does not go transparent. This is what the homewear is cut from.

What 96/4 means, and why not 100% cotton

Our fabric is 96% cotton and 4% elastane. Each part has one job.

The cotton does the breathing. It is a hollow, absorbent fibre: it takes moisture into itself rather than pushing it along the surface, which is why cotton feels cool rather than clammy. It also washes properly clean, so it does not build up the smell that synthetics hold on to.

The elastane does the remembering. Pure cotton jersey stretches during the day and stays stretched — by evening the waistband is loose and the leg openings have wandered. Around 4% elastane pulls the knit back to shape after every movement. It is the difference between underwear that lasts a season and underwear that lasts years.

Below roughly 5% elastane a knit does not recover properly. Much above 15% and you start feeling the synthetic instead of the cotton. Ten is the middle of that range.

The parts you do not see

The gusset is 100% cotton. Not a cost decision — a health one. That panel benefits from pure breathable cotton with no synthetic content at all, and it is the standard for a reason.

The seams are flatlock. A standard overlocked seam folds fabric over itself and creates a small ridge. Under a waistband, in heat, that ridge prints on skin. A flatlock seam butts the two edges together and stitches across, so the join sits level with the fabric.

The band is wide and soft rather than narrow elastic, so the same hold is spread over more skin instead of concentrated into one line.

How it behaves over time

Cotton jersey softens with every wash — the fibres relax and the hand gets better for the first several months. It also shrinks slightly on the first hot wash, which is why we recommend 30 °C from the start.

What kills it is heat and fabric softener. Hot water and tumble driers degrade elastane, and once the elastane goes the garment never holds shape again. Softener coats the cotton and reduces exactly the absorbency you bought it for. Wash cool, in a bag, dry flat, out of direct sun.

What we do not claim

Our cotton is not organic-certified, and we are not going to describe it as organic. It is good cotton jersey, sourced in Thailand and sewn in small batches in Phuket.

It is also not a technical wicking fabric. If you want something that dries fast during a run, that is polyester, and polyester is better at it. Cotton jersey is for the rest of the day — for heat, for home, for the hours when you would rather not feel your clothes at all.

You can see how it is cut across the collection in the catalogue, read the full fabric and care notes on the fabric page, or start with the Tat a Tat bralette and the Everyday Routine briefs.