Double Knit Fabric Manufacturing Process

You know that moment when a garment looks great on the hanger but starts twisting at the seams after two wears? Yeah, we’ve all been there. A lot of the time, it’s not the cut or the stitch—it’s the knit. And with double knits, what you see isn’t always what you get beneath the surface.

What Is Double Knit Fabric?

Double knit fabric isn’t just “thicker jersey.” That’s a common oversimplification. It’s a double-barrelled structure—two interlocked single knits produced simultaneously on a circular or flatbed machine, creating a fabric with stability, body, and minimal curl. Unlike single knits, which lean and roll like they’ve had one too many, double knits lie flat, resist runs, and handle tailoring better.

They’re built with two sets of needles—front and back—each feeding separate yarns or the same yarn in alternating courses. The result? A fabric that’s reversible (in most cases), moderately thick (typically 220–320 GSM), and dimensionally stable—ideal for structured knits, jackets, skirts, and even lightweight coats.

I’ve seen designers reach for double knits thinking they’re getting jersey-plus, only to get blindsided by stiffness or poor drape. The truth is, not all double knits are created equal. Some are tight and boardy; others are soft and fluid. It depends on the construction, not just the name.

How Double Knit Fabric Is Made

Machine Setup and Yarn Feeding

Double knits are typically made on a ribber-equipped circular knitting machine or a double jersey machine (like a links-links or interlock machine). The most common types are interlock and French terry double knit, though proprietary weft-knit variations exist.

Yarns are fed from two separate creels—front and back needle beds—allowing for different colors, textures, or fiber blends on each side. This dual-feed system is what gives double knits their sandwiched structure.

Needle selection matters. For fine gauge (18–24 gauge), you’re likely using round latch needles, 3.5–5.0 mm in diameter, depending on yarn count. Coarser gauges (12–16) handle heavier yarns but reduce drape. I once worked with a mill that insisted on 14-gauge for a drapey dress fabric—big mistake. The fabric came out like upholstery.

Yarn tension must be balanced. Too tight on the back feed? You get fabric skew. Too loose? Floats, skipped stitches, and seam puckering down the line.

Knitting Process: Interlock vs. Double Pique

There are two dominant double knit structures:

• Interlock: Alternating front and back loops interlock, creating a smooth, stable fabric with identical faces. It’s the most common, with GSM ranging from 240–300. Great for sheath dresses and structured tops.
• Double Pique (or Double Lacoste): Uses tuck and float stitches to create a textured, breathable surface. Often seen in polo shirts and sport separates. GSM runs higher—280–340—and it’s less prone to cling.

On the machine, the cam settings dictate stitch formation. A slight misalignment in the tuck cam can cause stitch distortion, especially in double pique. I’ve had rolls rejected because one needle bed was 0.2 mm off—barely noticeable, but enough to create a visible stripe under light.

Stitch length is critical. For interlock, aim for 5.8–6.4 mm; for double pique, 6.0–7.0 mm. Go shorter, and you lose stretch; go longer, and the fabric balloons during washing.

Case Study: A client wanted a double knit with wool-like handfeel but 4-way stretch. We tested three constructions: standard interlock, a spacer-based double knit, and a modified double pique with elastane in the back bar only. The first was too stiff, the second too bulky. The third worked—but only after adjusting the back stitch length by 0.3 mm to balance recovery. Took four samples. Not glamorous, but it worked.

Micro-note: Never assume GSM tells the full story. A 280 GSM interlock with fine merino can drape like 220 cotton jersey.

Post-Knitting Treatments

Relaxing and Heat Setting

Fresh off the machine, double knits are stressed—literally. Internal tensions from knitting cause skew and shrinkage later. So the first step? Relaxing under steam.

We typically run fabric through a tenter frame with low tension, applying moist heat (95–105°C) for 30–60 seconds. This stabilizes the structure before dyeing. Skip this, and you’ll see 5–7% shrinkage post-wash—even with pre-shrunk claims.

For synthetic blends (polyester/nylon), heat setting is non-negotiable. At 180–190°C for 45 seconds, you lock in dimensional stability. But watch the time: too long, and you bake the handfeel out of it. I once over-set a batch of poly-viscose double knit—it felt like cardboard. Had to reprocess with silicone softener, which added cost and batch variation.

Dyeing and Finishing

Double knits are usually dyed in jet dyeing machines (for small batches) or beam dyeing (for large runs). The dense structure means longer penetration time—add 15–20 minutes to standard cycles.

Temperature ramp rates matter. For cotton blends, go from 60°C to 98°C at 1.5°C per minute. Faster, and you get ring dyeing—color only on the surface. Slower, and productivity tanks.

After dyeing, finishing options vary:

• Brushing for peach-skin hand
• Sanforizing to reduce shrinkage to <3%
• Resin finishing for wrinkle resistance (common in travel wear)

But here’s a trade-off: resin improves performance but reduces breathability and increases stiffness. I’ve had customers complain their “wrinkle-free” double knit blazers felt like wearing a tent. We switched to a light silicone + mechanical compaction combo—better drape, slightly more care needed.

Case Study: A brand wanted a heathered black double knit for tailored pants. We started with a 70/30 poly/wool blend, but the wool barbed during brushing. Solution? Pre-dye the wool fibers separately, then blend and knit. Added a step, but avoided pilling. Pura Fabric ended up sourcing the yarn from a specialty Italian spinner—paid off in durability.

Micro-note: If you’re using elastane, keep dye temps under 100°C. Above that, you risk degrading the spandex and losing recovery.

Quality Control and Common Issues

Even a perfectly set machine can produce flawed fabric. Here’s what to watch for—and how to fix it.

Skew (Torque)

Skew is the bane of double knits. You cut a panel straight, and after washing, it twists like a corkscrew. Why? Uneven yarn tension or stitch length between front and back beds.

Fix:

• Measure skew on relaxed fabric: cut a 10×10 cm square, wash it, and check alignment. Acceptable skew: <2%.
• Adjust back bar tension or cam timing.
• Use balanced yarns (same count, same twist direction) on both sides.

I’ve seen factories blame the cutter when the real issue was a 0.1 mm needle bed misalignment. Always test before cutting.

Pilling and Surface Abrasion

Double knits pill less than single knits, but blends with short fibers (like cotton or low-grade polyester) still suffer. The tighter the structure, the better the resistance.

Quick checklist:

• Use long-staple cotton or high-tenacity polyester
• Maintain stitch uniformity (no float loops)
• Apply anti-pilling finish (Durable Press resins help)
• GSM >260 reduces surface exposure

One client’s double knit jackets started pilling at the elbows after three wears. We traced it to a cheaper, 1.2 denier polyester—switched to 1.0 denier with higher twist, and the problem vanished.

Seam Puckering

Even stable knits can pucker at seams if you’re not careful. Double knits have memory—especially after heat setting—so tension during sewing matters.

Tips:

• Use 75/11 or 80/12 needle (ballpoint or light jersey)
• Lower presser foot pressure
• Stitch length: 2.8–3.2 mm
• Consider a two-feed machine (differential feed + roller foot) for long seams

I prefer a slight negative differential (0.7–0.8) on side seams—it lets the fabric feed evenly without stretching.

Final Thought

Double knit isn’t a fallback fabric—it’s a deliberate choice. You trade some drape for stability, some softness for structure. But when you understand how it’s built—the needle beds, the stitch balance, the heat history—you stop fighting the material and start designing with it. I’ve ruined samples, misjudged handfeel, and chased GSM like it was a magic number. The best lessons came from the batches that didn’t work. So test early, question assumptions, and remember: the machine doesn’t care about your vision. It only responds to tension, timing, and temperature. Get those right, and the rest follows.