Topstitching

Topstitching is any line of stitching sewn from the right side of the garment, where it stays visible. It usually runs parallel to a seam or a finished edge: around a collar, along a front opening, across a yoke, down the outside leg of jeans, or around a pocket. Unlike construction seams, which are hidden inside, topstitching is part of how the garment looks, so its accuracy shows.

What it does

Topstitching does one or more of these jobs:

• Holds layers in place. It keeps facings from rolling to the outside, keeps seam allowances flat, and holds hems and pockets in position.
• Strengthens. It adds a second line of stitching through stressed seams, which is why workwear and jeans are topstitched so heavily. On a flat-felled seam, the topstitching is what holds the seam together.
• Decorates. A contrast thread or a double row turns a seam into a design line.
• Attaches. Patch pockets, lapped zippers and some waistbands are sewn on by topstitching.

Edgestitching and topstitching

The terms are often used loosely, but strictly:

• Edgestitching is sewn very close to an edge or seam, about 1/16"-1/8" (1.5-3 mm) away. It's crisp and subtle.
• Topstitching is sewn further away, usually 1/4"-3/8" (6-10 mm), and is more visible.

Many garments use both: an edgestitched row right at the edge with a topstitched row beside it, as on classic shirt collars and jeans.

Thread, needle and stitch length

• Stitch length. Go longer than for construction: about 3-3.5 mm with regular thread, 3.5-4 mm with heavy topstitching thread. Longer stitches look straighter and more deliberate.
• Thread. Regular all-purpose thread in a matching colour gives a quiet finish. For a bold line, use topstitching (heavy) thread in the needle, with regular thread in the bobbin. Two strands of regular thread through one needle is a substitute if you don't have heavy thread.
• Needle. Heavy thread needs a topstitch needle, which has a larger eye and a deeper groove so the thread doesn't fray or skip. For denim, a denim needle in size 90/14-100/16 works with regular thread.
• Tension. Heavy thread in the needle often needs the upper tension raised slightly. Test on a scrap with the same layers, including any seam allowances underneath.

Keeping it straight

• Use a guide. An edgestitch foot (with a metal blade that runs along the edge) makes edgestitching easy. For wider topstitching, use the edge of the presser foot, the needle plate lines, or move the needle position left or right so the foot edge sits on the fold.
• Press first. Topstitching follows whatever you've pressed. Press the edge crisply, rolling any seam slightly to the underside, before you start.
• Sew slowly and look at the guide, not the needle.
• Pivot at corners with the needle down in the fabric, so the corner is sharp and the rows stay parallel.
• Don't backstitch at the ends of visible topstitching, especially with heavy thread. Pull the threads to the wrong side and tie them off, or use a very short stitch for the first and last few stitches.
• Start in an inconspicuous place on a continuous line, such as the side seam of a hem rather than centre front.

When something goes wrong

Skipped stitches usually mean the needle is too small or worn for the thread and layers. Switch to a fresh topstitch or denim needle. Wavy topstitching comes from fabric stretching as it feeds: lengthen the stitch, reduce presser foot pressure if your machine allows it, or use a walking foot. Thread looping on the underside means the upper tension is too loose for heavy thread. Raise it a little at a time.