Exploring the World of Double Knit Fabrics: A Comprehensive Guide

You ever cut into a knit and suddenly it starts curling like a fern frond? Or worse—stretch it once too often and the seam gaps like a tired sweater? Yeah, we’ve all been there. That’s why double knits keep showing up in my go-to lineup, especially when I need something that behaves more like a woven but still moves like a knit should.

Manufacturing Process of Double Knit Fabrics

Double-knit fabrics don’t just happen—they’re engineered. The real magic starts with the machine setup, not the fiber. Most single knits rely on one needle bed and sinkers to control loop formation, but double knits skip that entirely. Instead, they use a circular knitting machine with two sets of needles: one in the dial (top) and one in the cylinder (bottom). These needles work in tandem, knitting both fabric layers simultaneously.

Setting Up the Knitting Machine

Before a single stitch is formed, the machine has to be dialed in. Circular machines used for double knits—like the Mayer & Cie or Santoni models—are calibrated so the dial and cylinder needles interlock loops precisely. Tension matters. Too tight, and the fabric fights itself; too loose, and you get inconsistent GSM. I once had a run where the GSM crept from 280 to 310 across a single dye lot just because the tension cam slipped. Took three test swatches and a call to the mill before we caught it.

Needle Configuration

The needles themselves are shorter and sturdier than those used in single-knit production. Butts on both dial and cylinder needles engage with cam systems that control knit, tuck, and float movements. Needle size? Typically between 18 and 24 gauge for most apparel-weight double knits. Finer gauges (28+) are possible but require tighter yarn counts and are more prone to snags.

Here’s the thing: because both layers are interlocked, the fabric doesn’t curl at the edges. That’s not just convenient—it means you can cut sharp corners on collars or hems without fusible interfacings fighting you.

The Knitting Cycles

Three cycles define the structure:

• Knit: Forms the base loop, standard stitch.
• Tuck: Holds the yarn without forming a new loop—adds loft and thickness.
• Float: Carries yarn across needles without knitting it—great for patterns but can create pressure points if overused.

When these cycles sync across both needle beds, you get stability. Misalignment? That’s how you end up with one side tighter than the other, leading to bias stretch or uneven shrinkage.

Loop Formation and Interweaving

Each stitch links front to back, creating a sandwich where the two layers are physically tied together. No glue, no bonding—just mechanical interlock. This is why double knits can hit 300+ GSM while still draping better than a medium-weight canvas. The interweaving also means the fabric resists runs. Snag one stitch? It won’t race down the row like it would in a jersey.

Elimination of Sinkers

Sinkers are those little metal fingers that help form loops in single knits. In double-knit machines, they’re redundant. The opposing needles handle loop control. This reduces mechanical wear and allows for higher production speeds—but only if the machine is perfectly aligned. I’ve seen mills skip routine cam alignment and end up with skewed stitch angles that caused 5% skew after washing.

Quality Control and Finishing

Testing isn’t an afterthought. At Pura Fabric, we run every double-knit batch through pilling (Martindale, 2000–5000 cycles), shrinkage (AATCC Test Method 135), and seam slippage checks. One batch of recycled polyester double knit we tested showed 4.8% shrinkage after home laundering—above our 3% threshold. We adjusted the heat setting in the sanforizing stage, dropped the temperature by 15°C, and brought it down to 2.6%. Small tweak, big difference.

Steam finishing is another lever. Most double knits respond well to moist heat—press at 150–160°C with a press cloth. Too hot? You’ll crush the loft. Too cool? Won’t set the shape. I prefer a clapper after steaming for crisper edges on collars.

Application and Versatility

These fabrics shine where structure meets movement. Think tailored knit pants, structured jackets, or A-line skirts that don’t balloon out. Because they don’t unravel, you can laser-cut or water-jet them into geometric shapes—something we did for a capsule collection with modular sleeve attachments. No overlocking needed.

Knitting Machines: Versatility in Fabric Production

Not all machines are built for double knits. While circular machines dominate, flatbed V-bed machines (like Stoll or Shima Seiki) can produce double-knit structures too—especially for shaped panels or full-garment knitting. These are slower but allow for variable stitch patterning across the piece.

One designer I worked with wanted a gradient tuck stitch on the bodice but full knit on the sleeves. We used a Shima machine with independent needle control—programmed the tuck density to increase gradually across 40 rows. Took two test runs and a lot of CAM file tweaking, but the fabric moved exactly how she wanted: stiff at the waist, soft at the shoulder.

Flatbeds also minimize waste. You knit only what you need. For small runs or zero-waste patterns, that’s a game-changer. But for bulk production? Circular machines still win on speed and consistency.

Unique Characteristics of Double Knit Fabrics

Double knits are the quiet professionals of the knit world. They don’t scream for attention, but they hold their shape, resist curl, and take tailoring well. Here’s what sets them apart:

• Two-way stretch, usually more balanced front-to-back than single knits
• No edge curl, thanks to symmetrical loop structure
• Higher density—typically 260–340 GSM for apparel, up to 400+ for outerwear
• Seam durability—less prone to popping under tension
• Dye consistency—the tight structure can resist penetration, so we pre-condition all our double knits with wetting agents before dyeing

One thing I’ve noticed: double knits with a high elastane content (above 5%) can develop “memory creases” if stored folded too long. Not a defect, but a quirk. I tell clients to hang them or roll them if storing for more than a few weeks.

Micro-note: A client once used a double-knit rayon/nylon blend for a structured blazer. After three wears, the underarm area started to pill. We traced it back to friction + tight armhole pattern. Solution? We added a nylon lining and reduced elastane from 8% to 4%. Problem solved.

Single vs. Double Knit Fabrics: A Comparative Overview

Let’s cut through the noise. Single knits—like jersey, rib, or interlock—are light, drapey, and economical. But they come with trade-offs:

Single knits are perfect for T-shirts, loungewear, or linings. But if you’re making something that needs to hold a line—like a pencil skirt or a bomber jacket—double knit is the smarter call.

Case Study: The Tailored Knit Dress That Almost Failed
A designer came to us wanting a “knit that looks like wool crepe.” She needed drape, recovery, and clean edges—no rolling, no sagging. We tested three single knits first. All curled at the hem after washing. Then we tried a 300 GSM polyester/viscose double knit with 4% elastane. First sample looked great, but after wear-testing, the side seams gapped.
Why? The fabric had good recovery, but the pattern was cut on the bias without stabilization. We suggested:

1. Narrower seam allowances (1/4” instead of 3/8”)
2. Stay stitching 1/8” from the edge
3. Lightweight tricot tape on high-stress seams
   Second sample held perfectly. The lesson? Even stable fabrics need smart construction.

Micro-note: I still prefer single knits for sleepwear. Double knits feel too “put together” for bedtime.

Case Study: Choosing Between Weight and Drape
We were developing a travel blazer—meant to be packable, wrinkle-resistant, and warm. Two options:

• Option A: 280 GSM double knit, 68% TENCEL™, 28% nylon, 4% elastane
• Option B: 330 GSM, 75% recycled polyester, 20% wool, 5% elastane

Option A was softer, draped better, but lacked structure. Option B held its shape but felt stiff when folded. After three prototypes, we went hybrid: used Option A for the body, Option B for collar and lapels. Interfaced the front panels lightly. The result? A blazer that rolled into a tote without creasing and still looked tailored.
This wasn’t about picking the “best” fabric—it was about matching material behavior to garment function.

Final Thought

Double knits aren’t magic, but they’re close. They ask for attention during production—machine alignment, heat settings, seam techniques—but they give back in durability and design freedom. I’ve seen them used for everything from ballet warm-ups to architectural fashion installations. The key isn’t just knowing what they can do, but understanding when to use them. Sometimes the best fabric choice isn’t the thickest or the shiniest—it’s the one that stays out of the way while doing its job.