What is sweater knit fabric?

Sweater knit fabric is a category of textiles designed to mimic the look and feel of hand-knitted or fully-fashioned knitwear, but it is produced in continuous rolls (yardage) on circular knitting machines or Raschel machines.

For a manufacturer or designer, it is crucial to distinguish between “Sweater Knit Fabric” (Cut-and-Sew) and “True Knitwear” (Fully Fashioned).

Here is the technical breakdown:

1. The Definition (Cut-and-Sew vs. Fully Fashioned)

• True Knitwear (Fully Fashioned): This is what you produce on Stoll or Shima Seiki flatbed machines.¹ The front, back, and sleeves are knitted to the specific shape of the garment. There is no cutting, and minimal waste.²

• Sweater Knit Fabric (Yardage): This is produced on large-diameter circular knitting machines. It comes in long rolls, just like t-shirt jersey or denim. You lay patterns on top, cut the shapes out, and sew them together using an overlocker (serger).

  • The Advantage: It is much faster and cheaper to mass-produce.

  • The Disadvantage: It has “raw edges” that must be hemmed, and it lacks the refined “fashioned” marks at the armhole.

2. Common Types of Sweater Knit Fabric

If you are sourcing this material, you will often encounter these specific commercial names:

• Hacci (or Hatchi): The most common sweater knit fabric. It is a lightweight, open-knit fabric usually made from polyester/rayon/spandex blends.³ It has a “loopy” texture and is extremely drapey.⁴ It is used for “slouchy” tops and cardigans found in fast-fashion (e.g., Forever 21, H&M).⁵

• Raschel Knit: A type of warp knit that looks like crochet or lace.⁶ It is stable (doesn’t stretch as much) and has a very open, holey structure.

• Sweater Fleece: A hybrid fabric. The face looks like a marled sweater (knit texture), but the back is brushed fleece (like a sweatshirt). This gives the look of a sweater with the stability and warmth of a hoodie. Popularized by brands like Patagonia (Better Sweater).

• Rib Knit Fabric: Sold in rolls, this is a 1×1, 2×2, or 4×2 rib structure. It is highly elastic and often used for fitted turtle necks or trim.

3. Technical Characteristics

• Gauge: Sweater knit fabrics are coarser than standard jersey (t-shirts), typically ranging from 9GG to 18GG (whereas t-shirts are 24GG+).

• Yarn Count: They use lower count (thicker) yarns or loosely spun yarns to create “loft” (fluffiness).

• Stability (The Challenge): Unlike stable woven fabrics, sweater knits are unstable.

  • Curling: The edges will curl aggressively when cut.

  • Running: If a thread is snagged, it can cause a “ladder” or run through the whole piece.⁷

  • Growth: When hung on a hanger, the fabric can stretch vertically under its own weight (growing 2-3 inches).

4. How to Identify It

If you pick up a garment and are unsure if it is “Sweater Knit Fabric” (Cut-and-Sew) or “True Knitwear,” look at the side seams inside:

• If you see an overlock/serged stitch (a messy tangle of thread wrapping the edge): It is Sweater Knit Fabric (Cut-and-Sew).

• If you see a clean “linked” seam (looks like a small chain): It is True Knitwear (Fully Fashioned).

Summary

Sweater Knit Fabric is the industrial solution for making “sweater-like” garments at the speed and cost of T-shirt manufacturing. It provides the aesthetic of a sweater (texture, warmth) but handles like a piece of cloth.