When a seam is curved, turning the fabric right side out can cause pulling or wrinkling. To make curved seams flat, use the tips of your shears to notch or clip the seam allowance, taking care not to cut into the stitching.
Remember to clip inward (concave) curves and notch outward (convex) curves.
You’ll often see inward (concave) curves at underarm seams or necklines that have a facing.
Without clipping an inward (concave) curve, you can see that it’s almost impossible to get the curve to turn neatly to the inside.
Use the tip of your scissors to clip at even intervals along the curve, being careful not to cut into the stitch line.
You can see that after clipping, your seam will appear neat and flat.
If you want a smooth, round curve, you’ll have to take an extra step to reduce bulk on outward (convex) curves.
An outward (convex) curve will appear lumpy if you do not reduce the bulk of the seam allowance. In fact, you might not even be able to turn it to the right side.
To notch, use the tip of your scissors to cut wedge shapes into the seam allowance at even intervals, being careful not to cut into the stitching.
You can see that after pressing, your curve is not bulky.
Put your new skills to the test. Try sewing:
Clip the neckline of the York Top for a smooth curve.
Clipping will also help keep the neckline smooth on the Kenedy dress for a smooth curve.
After attaching the neckline facing to the Reggie dress, make sure to clip the seam allowance.