Definition
A notch is a small mark on the cutting line of a pattern piece that shows where it must line up with a matching notch on another piece.
Notches work like jigsaw tabs. Before sewing two pieces together, you match their notches so the seam is eased evenly and nothing ends up twisted or too long. They also mark center front, dart positions, pleat folds and the point of the sleeve cap that meets the shoulder seam.
A common convention, used by the large pattern companies, is a single notch on front seams and a double notch on back seams, so a sleeve cannot go into the wrong armhole. Triple notches appear on long seams where a third match point helps.
How to transfer them:
- Snip 3 to 5 mm (1/8 to 3/16 in) into the seam allowance, never past the stitching line.
- On loosely woven fabric, or if you might let the seam out later, cut a small triangle outward instead, or mark the notch with chalk.
Do not confuse pattern notches with notching seam allowances, which means cutting small wedges out of a curved seam after sewing so it lies flat (see clipping and notching). The British term balance mark describes their purpose well: they keep the garment balanced.
Notches, dots and other symbols are explained in how to read a sewing pattern.