Topstitching

Topstitching is any stitch line deliberately sewn on the visible outer surface of a finished garment, rather than hidden inside a seam allowance; it can run along a collar edge, a placket, a hem, or a yoke seam, typically 1/8 to 1/4 inch from the finished edge. It's frequently done in a contrasting thread color specifically so it reads as a design detail rather than blending into the fabric.

Polo plackets, denim pocket bags, and hoodie pouch pockets all use topstitching both structurally, since it flattens and reinforces the seam underneath, and visually, as with the orange stitching on a pair of jeans or the contrast collar stitch on a polo. We've had brands request topstitching removed from a mockup entirely because the thread color was fighting with an embroidered logo sitting right next to it.

When you're speccing custom apparel, check whether topstitching thread color is fixed to the blank or adjustable; some manufacturers offer contrast colors as an add-on, worth coordinating with your print or embroidery colors so the two don't clash on the finished piece.

A common misconception is that topstitching is purely decorative. On a lot of garments it's doing real structural work, flattening a folded seam, keeping a facing from rolling, and the visible line is simply a side effect of stitching from the outside to get at that seam.