This article describes textile uses. Polos are in preparation in Clothix; a suitable fabric does not make that garment family available in the workspace.
What you get for the extra needle bed
A balanced fabric. Single jersey curls because its face and back pull unequally. Interlock's two halves pull against each other, so a raw edge stays put. That opens up construction a jersey can't do: raw or lightly finished edges, self-fabric bindings that don't fight you, plackets that stay flat.
Dimensional stability. It stretches less than jersey and holds its shape better through wear and washing. A polo made in interlock still has a collar that stands after a year; the same polo in jersey doesn't.
Both sides usable. Handy for anything where the inside shows — a folded cuff, a turned placket, an inside-out detail.
More weight for the same feel. Two layers of loops means an interlock is heavier than a jersey of the same apparent thickness. A 240 g/m² interlock feels closer to a 180 g/m² jersey than to a 240 jersey, which trips people up when they spec by number.
Interlock vs jersey, side by side
| Single jersey | Interlock | |
|---|---|---|
| Needle beds | One | Two |
| Raw edge | Curls | Lies flat |
| Faces | Smooth front, looped back | Smooth both sides |
| Crosswise stretch | High | Moderate |
| Shape retention | Lower | Higher |
| Usual weight | 140–220 g/m² | 200–260 g/m² |
| Cost per metre | Lower | Higher — slower to knit |
| Typical use | T-shirts, tanks | Polos, structured tees, kidswear |
Interlock and pique
Worth separating, because the words get mixed. Pique is also a double knit, but with a deliberately raised, textured surface — the small waffle pattern you see on a polo. Interlock is smooth. Both are stable, both hold a collar; pique is the one people recognise as a polo fabric, and interlock is the one used when a polo should read as plain. Which to choose for a polo.
Speccing it
- Structure — "interlock", and say if you mean pique instead, because a mill will knit exactly what you write.
- Weight in g/m², bearing in mind the apparent-thickness mismatch above.
- Composition and yarn spec, same as any knit.
- Shrinkage, length and width. Interlock generally moves less than jersey, which is one of its selling points, and the mill should still give you the number.
In the Clothix library the interlock profile is INT-COT-240: cotton, 240 g/m². It's the entry to use for polos and for a t-shirt that should hold a squarer line than jersey allows.
Jersey, for the comparison · polo construction · weight and GSM · all five structures