Manufacturer · Fashion & Home Accessories
Seams are reinforced with herringbone tape by sewing a narrow, non-stretch tape into the seam together with the fabric. It takes the load and prevents the seam from stretching during wear and washing. The seams most often reinforced are shoulder seams on knitwear, necklines, jacket lapels and pocket openings.
Why seam reinforcement with tape is needed
Knitwear, as well as woven fabrics cut on the bias, stretch under their own weight. The shoulder seam of a heavy jumper gradually lengthens, the neckline of a T-shirt "opens up" and the pocket opening on trousers bulges. If the seam is reinforced, it keeps the length built into the pattern. Herringbone tape is suited to this task because it is dense, practically does not stretch lengthwise and is thin enough not to be felt.
Which seams are reinforced
| Position | Product | Recommended width | Purpose |
|---|---|---|---|
| Shoulder seam | Knitwear, jumpers, T-shirts, jackets | 6–10 mm | So the shoulder does not lengthen |
| Neckline and back neck | T-shirts, blouses, dresses | 6–10 mm | So the neckline does not gape |
| Lapel roll line | Jackets, coats | 6–12 mm | So the lapel lies against the chest |
| Pocket opening | Trousers, skirts, jackets | 10–15 mm | So the pocket does not bulge |
| Waist seam | Jersey dresses, jumpsuits | 10–15 mm | So the waist does not drop |
| Zip edge | Products made of stretch fabrics | 10–12 mm | So the zip does not ripple |
How the tape is sewn in – step by step
Shoulder seam on knitwear
- Cut the tape to the length of the shoulder seam on the pattern, not on the already stretched fabric.
- Place the two parts right sides together and lay the tape on the seam line, on the back piece side.
- Sew with an overlock or straight stitch so that the needle passes through the middle of the tape.
- Do not stretch either the fabric or the tape. If the fabric stretched slightly during cutting, ease it evenly along the tape.
- Press the seam allowance towards the back.
Neckline and lapel
On the neckline, the tape is laid exactly along the seam line, and on curves it is shaped slightly with steam before sewing. On a jacket lapel, the tape is placed on the inside along the roll line and sewn with invisible stitches. It is often pulled minimally, by about 5–10 mm over the whole length, to draw the lapel towards the body. This is a classic tailoring technique that requires a test on the specific fabric.
Pocket opening
The tape is placed along the edge of the opening, on the inside, and caught by the seam that joins the facing. This way the opening does not stretch when hands are put in and keeps its straight line.
Which tape to choose
- Width: 6–10 mm for knitwear and light fabrics; up to 15 mm for heavier woven fabrics and pockets.
- Thickness: the thinner the fabric, the thinner the tape. A thick tape in light jersey shows through on the outside as a ridge.
- Material: the tape must behave like the fabric in the wash. Cotton tape on cotton fabric is a natural combination; for synthetic and blended fabrics, a polyester or blended tape that does not shrink is safer.
- Colour: white, black or natural are usually enough, because the tape is hidden. For sheer or very light fabrics, choose a shade close to the fabric.
Suitable widths and materials are collected in our herringbone tape category.
Threads and machine settings
Use polyester sewing thread, which is strong and does not break under seam load. A 70–80 needle for knitwear and 80–90 for denser woven fabrics is a good starting point. With an overlocker, check that the knife does not cut the tape – it must remain intact in the seam allowance. You will find suitable threads in our threads category.
Common mistakes
- The tape is cut to the stretched fabric. The reinforcement then simply "fixes" an already stretched seam. Always measure from the paper pattern.
- The tape is stretched during sewing. The seam puckers and the shoulder looks crumpled.
- Tape that is too wide or thick. The seam becomes stiff and shows on the outside.
- Different shrinkage. Cotton tape that has not been pre-soaked can shorten the seam of a synthetic garment after the first wash.
- The tape is not caught by the seam. If the needle only runs along its edge, the tape slips out and does not work.
- The tape is left out of the sample. If the sample garment is sewn without reinforcement and the production run with it, the measurements and fit may differ. Sew the sample exactly as the run will be sewn.
Herringbone tape or fusible stay tape
Heat-fusible stabilising tapes are also used in production. They are fused with an iron or press and are quick to apply, but they can come unstuck with frequent washing and make the seam stiffer. Herringbone tape is sewn in mechanically, does not depend on adhesive and preserves the softness of the seam. For quality knitwear and jackets, many manufacturers prefer it. You will find other types of tape for garment production in our ribbons and tapes section.
Checking the sample
Once you have sewn a sample garment with reinforced seams, measure the shoulder seam and neckline and compare them with the pattern. Wash the sample once or twice and measure again. If the measurements have remained the same and the seam lies smoothly, the tape and technique are correctly chosen for the run.
Tape for your production
Polkom is a manufacturer and wholesaler of haberdashery for clothing based in Sofia. We supply narrow herringbone tape in cotton, polyester and blends for seam reinforcement, in Pantone colours and on rolls for series production, with delivery across the EU. Minimum quantities depend on the article. For samples and advice on the right width, contact us via our contact page.
