A collar that sits well is mostly about what you do to the seam allowances, not about the stitching.
Interface the upper collar — or both pieces on soft fabric. A collar without interfacing has no structure and rolls limply.
Cut the under collar very slightly smaller — 2 to 3 mm around the outer edges. This forces the seam to roll to the underside where it cannot be seen, which is what makes a collar look tailored.
Sew, then trim and grade. Trim the seam allowances to different widths — the one nearest the outside stays widest — so they do not form a ridge. Trim across the points close to the stitching.
Turn and push the points out with something blunt. Never scissors or a pin.
Roll the seam to the underside between your fingers before pressing, so no seam line is visible from the top.
Understitch the outer edge if the collar style allows — it holds the under collar in place permanently.
Press over a curved surface if the collar is shaped. Pressing a rolled collar flat creases in a line that will show.
Then attach it carefully, matching the centre back and the notches, and clipping the neckline curve so it can spread.
Questions people actually ask
My collar points are rounded.
Not enough trimmed before turning, and turned with something too blunt or too sharp. Trim closer, taper the sides, and use a proper point turner.
My collar will not lie flat.
Usually the neckline curve was not clipped, so the seam allowance is pulling. Clip almost to the stitching at intervals.
Last reviewed 2026-08-11