Oh curved seams. You tricky little things, you.
Have you ever sewn a garment, and a seam just don’t seem to lay right? Or it bubbles or twists in a weird way? Annoying, I know. Chances are, you forgot to clip or notch your curved edge. When you work with curved seams, you can either end up with excess bulk or a lot of pulling and tugging. This is because the length of your stitch line measures differently from the length of the edge of your fabric. So when it is turned right side out, it doesn’t conform correctly or lie flat. You can solve this by either clipping or notching your seam allowance, to allow for that adjustment.
Another time it comes in handy? When trying to attach a curved edge to a straight edge. But we’ll get to that in a minute.
So… when do you clip and when do you notch? Read on to find out!
Clipping is done on concave curves. Think inward, sunken in, bowl, or valley. These type of edges would include necklines, armholes, etc.
For concave curves, you simply clip, or snip, into the seam allowance at a vertical angle to the stitching. You want to get as close to the stitching as possible, without actually clipping through it. Do this about every 1/2” or so. Too much clipping can weaken the fabric, but not enough won’t provide the necessary movement.
Clipping like this will allow the seam allowance to spread / fan out, giving it the necessary movement to conform to the right shape when it’s turned right side out. See the last photo above? Look how nice and flat and neat it looks! No twisting and pulling!
Clipping also comes in handy when attaching a curved edge to a straight edge. Like attaching the curved waist of the Cascade skirt to the straight edge of the waistband. You just sew a 5/8″ staystitch around the edge of the curve (the skirt waist), and then clip as described above. The curve will spread and lie flat, making it easier to join it to the flat waistband.
Notching is done on convex curves. Think outward, hill, or mountain. You will find these in princess seam bustlines, or even the bottom edge of a dipped hem.
For a convex curve, you need to notch out little v shapes from the seam allowance. Again, every 1/2” or so. And to, but not through, the stitching.
You see, when a curve like this is turned right side out, there ends up being too much fabric in the seam allowance. Which causes it to bunch up. Unlike clipping, which allows fabric to spread out, notching enables it to come closer together without the bulk, by removing the excess fabric. So it will now lie neat and flat without any bunching, like the last photo above!
Does that make sense? Do you have any of your own tips and tricks when it comes to curved edges?