A mitre removes the surplus fabric at a corner by folding it out on the diagonal, so two hems meet at 45 degrees with no bulk. It is how table linen, napkins, quilt bindings and hemmed corners on curtains are finished.
The reliable method for a hemmed corner.
One. Press both hems fully — including the second fold if it is a double hem — right into the corner. Then open them both out flat. The creases you have just made are your map.
Two. Fold the corner of the fabric diagonally so that the two sets of creases meet exactly. Press that diagonal.
Three. Either fold along that diagonal and stitch nothing — which is the simple folded mitre, adequate on light fabric — or open it out, fold the corner right sides together along the diagonal crease, stitch along it, trim to 6 mm, and turn. The stitched version is flatter and much neater on anything with body.
Four. Refold both hems. They now meet cleanly at the corner with the surplus enclosed.
Trim the corner point before turning so it turns sharply, and push it out with a blunt point turner rather than scissors.
For a mitred binding corner, stop stitching one seam allowance width from the corner, backstitch, fold the binding up at 45 degrees, then back down along the next edge, and start again from the fold. That fold becomes the mitre when the binding is turned.
Accuracy in the pressing decides everything. A mitre is only as square as the creases it was folded from.
Questions people actually ask
Should I stitch the diagonal?
On anything heavier than lawn, yes. A stitched and trimmed mitre lies far flatter than a folded one.
My mitres are not symmetrical.
The two hems were pressed to different depths. Measure and press both hems identically before folding the diagonal.
Last reviewed 2026-08-11