Woven Label Stitching Methods: Sewing, Overlock, Ultrasonic and Heat Bonding

How a woven label is attached decides how the inside of a garment looks, how it feels against the skin, and how much rework the sewing line generates. The same label can give a very different hand feel, cost and durability depending on whether it is lockstitched, overlocked or ultrasonically welded. This guide breaks down the mainstream methods so you can fix the attachment at sample stage.

The short answer: for most apparel brands the best default is a folded edge lockstitched in place, because it is the gentlest on the fabric and gives the most consistent look. Overlock is faster but leaves an exposed edge and feels firmer, so it suits denim and workwear. Ultrasonic welding and heat bonding remove the sewing step and suit synthetics and sportswear, but they depend on the fibre content.

1. Why Attachment Should Be Decided at Sample Stage

When specifying a woven label, buyers focus on yarn, density and colour, and leave the attachment method to the factory. Once bulk production starts, changing it is expensive: it drives rework rates, the risk of damaging the fabric, and what the customer experiences when removing the label. Many quality complaints — labels that scratch the skin, curled edges, fraying after washing, stitch lines embossing thin fabric — trace back not to the label but to how it was attached and where.

2. Five Main Attachment Methods Compared

3. Folding, Hot-Cut Edges and Fraying

The two ends of a woven label are where trouble starts: cut yarns are exposed and fray after the first wash. Choosing the right edge finish is far cheaper than reworking later.

• Hot-cut edge: a heated blade melts the warp and weft, ideal for polyester and other synthetics — the edge seals itself with no fray; on pure cotton it works poorly, so use a fold instead.
• Laser cutting: cuts custom outlines and seals the edge in one pass, but dark fabrics can show a yellowish burn line — confirm at sample stage.
• Folding (centre fold or end folds): tucking the raw edge inside the fold before sewing is the safest option for any fabric, especially cotton and blends.
• Sealed or coated selvedge: some labels are woven with a finished edge structure, needing no secondary process — higher cost, cleanest look.

4. Stitch Density, Tension and Fabric Match

• Stitch density: typically 2.5–3.5 mm. Too dense cuts thin fabric; too sparse holds poorly and the label can be pulled off.
• Tension: excess bobbin tension embosses thin fabric and can ripple the label; on knits, fine-tune feed dogs and presser-foot pressure.
• Needle and thread: fine needles (size 9–11) and fine thread for light fabric, size 14–16 for heavy; match thread colour to the label background to avoid a busy stitch line inside the garment.
• Placement: centre-back neck, side seam or hem — each position makes its own demands; for skin-contact spots, prefer a folded-edge lockstitch to reduce rubbing.

5. Common Defects and Their Causes

• Curling or lifting edges: usually excess tension or too narrow a fold, most visible after washing;
• Fraying: an unsealed cut edge or a stitch line too close to the edge, letting yarns rub free;
• Waviness or puckering: different shrinkage between label and fabric, or stretching during feeding — control the feed tension;
• Broken needles or skipped stitches: often at thick-to-thin transitions or with the wrong needle size — run test seams at pilot stage;
• Needle holes or adhesive bleed: wrong heat or pressure in bonding squeezes glue out, and wrong ultrasonic power burns through synthetics.

6. Sampling and Approval Checklist

• Confirm the label's edge finish (hot-cut, folded, laser) matches the fabric composition;
• Test-sew on the actual bulk fabric, not a substitute — performance varies a lot with weight and stretch;
• Re-check edges, curling and stitching after at least 3 washes to validate durability;
• Record needle size, stitch density, thread spec and tension settings as the bulk process spec and inspection basis.