Curved Seam Applications:
Neck lines, armscye
Design features (V1105 at left)
Curved seams and finishes are essential in clothing construction. They appear in obvious places such as the princess seams in the dress (Vogue 1237) at left, or even as design features such as in the jacket (also Vogue 1237) with curved horizontal seams. Here the seams do, no doubt, provide fit too. Curves are also pretty obvious in neck lines and in sleeveless tops and dresses. It's also fun to introduce new seams in order to introduce design features or color blocking. as in the simple top at right.
Here are some of my favorite techniques:
This requires seam allowances (SA) of ¼” or less, works best in pieces where precision is not required. It's a good idea to do this before cutting out a pattern piece. Place the two fabric pieces right side up on your cutting surface, overlapping enough to allow for the curve. Gently carve out the curve within the overlapped portions using a rotary cutter. Separate and discard the part cut off of each piece. Pin right sides together, just at the beginning. Sew slowly with stitch length of about 2.0, adjusting the SAs to meet as you encounter curves. Sew especially slowly around the curves. Press to one side. Now you can cut out the pattern piece that will contain this design feature or color blocking. Again the simple top above illustrates this technique.
Sewing concave to convex (e.g., princess seams):
- Staystitch 1-2 threads inside SA on both the concave and the convex curves. I use a 2.0 stitch length or less, depending on the fabric. This allows you to clip and notch BEFORE sewing.
- Clip the concave curve. Notch the convex curve.
- Pin at beginning of seam, end of seam and matching any notches or other registration marks you have. Because you have already clipped and notched, you should be able to pin a more-or-less straight seam to sew. Sew slowly, staying outside of the staystitching, opening clips and closing notches as needed.
- Sew seam using your normal stitch length. Press open or finish seam as desired.
- Staystitch inside the 5/8” mark. The reason is to avoid distortions as you handle the pieces.
- Sew seam using usual SA, e.g., 5/8”.
- Grade seam so that one SA is no less than ¼”; the other SA must be more than ¼”.
- Clip the curves one layer at a time. Do not clip both layers together. Clip each separately so that the clips are staggered.
- Press, turn, press in place, favoring the outside fabric slightly.
- Top-stitch, understitch or use another method to keep the layers from shifting.
Creating your own curves (similar to brute force, but with more accurate results)
- Draw a gentle curve free-hand onto the pattern piece tissue.
- Draw grain line to each side of the curve.
- Create registration marks (notches) - at least one per curve - by marking across the curve.
- Trace each piece onto a separate piece of pattern tissue, leaving enough space by the curved edge to add SA.
- Add desired SA, usually 5/8”, to the new seam line of each piece. Make sure to mark the notches you created in step 2.
- Cut out pattern tissue for each new piece.
- Cut out fabric using these new pattern pieces. Be sure to mark notches (registration marks).
- Sew the two pieces together following the “concave to convex” method above.