Single Jersey vs Interlock: Choosing a Polyester Knit
The difference between single-bed jersey and double-bed interlock — hand, stability, curling, weight and which suits which product.
Single jersey (süprem) and interlock are the two most common structures in polyester knitting. Both are made on circular knitting machines but use different needle-bed arrangements; that difference directly sets the fabric's hand, thickness, stability and behaviour.
Single jersey (single bed)
Knitted on one needle bed with a single yarn system. It is thin, light, stretchy and economical. The face shows knit loops (a V appearance), the back purl loops; the two sides differ. Ideal for lightweight performance tees, linings and products that need fluid drape.
Interlock (double bed)
Knitted on two needle beds by interlocking two single-jersey structures. Both faces look identical and smooth (double-faced), and the fabric is thicker, fuller and more dimensionally stable. Suited to heavier tees, polos, sweatshirts and structured pieces.
Edge curling and spirality
When cut, single jersey tends to curl at the edges and, especially in single-ply yarn, can show spirality (seam twisting), which calls for care in cutting and sewing. Interlock's balanced structure means edges do not curl and it resists spirality far better, which makes garment-making easier.
Quick comparison
| Property | Single jersey (single bed) | Interlock (double bed) |
|---|---|---|
| Hand | Thin, fluid | Full, structured |
| Surface | Two different faces | Two identical smooth faces |
| Stability | Less stable | More stable; no curling, little spirality |
| Weight | Light (~120–180 g/m²) | Heavy (~180–280 g/m²) |
| Cost / yield | Faster, cheaper | Needs more yarn and time |
| Use | Light tee, lining | Heavy tee, polo, sweatshirt |
Which to choose?
Choose single jersey when lightness, stretch and low cost lead; choose interlock when opacity, a durable hand, stability and easy garment-making lead. Knitted from the same yarn, interlock yields a heavier, more opaque fabric than single jersey.
Frequently asked questions
Is single jersey or interlock more stable?
Interlock. Its double-bed (two needle beds) structure makes both faces smooth and opaque, so edges do not curl and it is more dimensionally stable. Single jersey is single-bed: lighter and stretchier, but its edges curl and opacity is weak at low weights.
Which product needs single jersey, and which needs interlock?
Single jersey suits light tees, innerwear and French terry bases (≈120–330 g/m²). Interlock is preferred for jerseys, polos, ponte and structured tops (≈170–360 g/m²).