Thursday, 8 May 2014

Sewing Curved Seams

Ever wondered why your garment is pulling in odd places or why it is getting all bunched up? It probably must be that you haven't clipped or notched rightly at the curves.
I've explained below convex, concave - when to clip and notch. It is a long post so grab a cuppa and enjoy!!
Sewing curved seams hems- clipping notching concave convex

Jump to Section:
1. How to sew a curve
2. Sew concave to convex
3. Sew concave seams
4. Sew convex seams

Sewing - What is concave and convex
A curve could essentially be of 2 types  - Concave OR Convex: 
CONCAVE - The front of your spoon which goes towards the inside to hold the food. Have a look and you'll see yourself upside down. I remember learning about this at school :). Do you?
Think of it like a valley.

CONVEX: The back of the spoon which is like a hill.

Sewing curved seams takes some practise but very importantly there are techniques to follow - and this is what I'm going to show you today:

Stitching curves

How to sew a curved edge

how to sew a curve

- I use my left hand to glide and right hand (not shown as I used it to click) to remove pins and precision the glide of the left hand.
- I go really slow
How to pin curves
 - When the curve seems really difficult to manage I put the needle down
Pivot to sew curves
 pivot to the angle I need making sure there are no sharp corners and continue to sew.




How to sew concave to convex

How to sew concave to convex edge - How to sew opposing curves

 Examples: Yoke (convex) attached to the body piece (concave).

Nightie pattern Nightie pattern sewing curves
  This involves some thinking - Let's have a look at at the below pieces of concave and convex fabrics that we will be sewing together:
How to sew curved seams tutorial Tricks and logic to sew opposing curved seams neatly
At first glance you may think that the purple convex fabric is much larger than the white concave fabric and that it can never be sewn together. Right?? Now look closely. The blue colour stitching line (not very visible after I've put some dashed lines, sorry) is 13 cm on both fabrics.
Overlap the 2 fabrics on the blue stiching line and you will see it fits perfectly. (right image)
Now how to sew it??
I think of it this way: We want to the edge length to be same as the stitching length.
Concave - The edge (11 cm) is smaller than the stitching line (13 cm). How to make the edge same as the stiching line? Cut/slit it so they can spread.
Convex -  The edge (15 cm) is longer than the stitching line (13 cm). How to make the edge same as the stiching line? Notch it up so they can overlap.

Don't want to think too much? Ok, Remember this:



Steps to sew:
I'm notching up the convex here but you could slit the concave - Just do one of them or its just too hard to make sure you sew it correctly.
Stitching curves - clipping and notching explained
 1. Stay stitch (just normal stitch) on the stitching line (I prefer to do it about 0.1 or 0.2 cm away from stitching line towards the edge). Next cut  notches about 3 cm away to start with. The interval depends on the how deep the curve is. I generally start with 3 cm and cut more if required.
Note that the notches reach the stitching line but not cut through it.
Sewing curved seams - clipping notching concave convex
 2. Start to pin the convex to concave at the stitching line (blue here).
How to pin curves before sewing
 3. Don't worry!! It will get bunched up because we haven't yet cut the concave piece.
Tricks to sew curves
 4. Sew at the stitching line with the convex piece on top being very careful there are not have any puckers on the concave piece.
How to sew curves - concave clipping, convex notching
 5. Grrrr!! Got a slight one there. I cannot be bothered to unpick and do it again for this little one. I'm sure I can fix this.
Successful perfect curves
 6. This is how it looks on inside. Still all curled up.
How to sew curves - concave clipping, convex notching
7. Now cut the concave being careful not to cut through the stitch.
How to trim curves

8. Trim the seam. I trim to about 0.7 cm.
Sewing opposite curves together
9. That little pucker shows up here!!
Pressing curves for a smooth finish

10. Nothing that a hot iron can't fix!!

How to sew 2 convex curves

How to sew 2 convex curves

Cape coat sewing curves

Example: Bottom curve of the most complemented cape coat
Remember -


How to sew convex curves together
1. Sew on the stitching line with right sides together
How to notch convex curves
2. Cut triangular notches on one of the fabric pieces.
What is notching
3. On the reverse cut notches in between the notches of the white fabric.
This way:
1. When you iron the fabric it will not sink inside of the triangles.
2. If it is sheer fabric you will not be able to see the triangles from outside. (If it is very sheer you'll still be though!)
Sewing curves - Alternate notches for a smooth curve
4. Another pic for clarity!!
Clipping curves
5. Trim the seam allowance to about 0.7 cm
How to get flat laying curves
6. At this point I turn the fabric on right side and see if the fabric still overlapping after the notches. It is here so I create more notches.
Notching convex for a smooth curve
7. Closer notches this time!!
How to sew curves - concave clipping, convex notching
8. The inside this time doesn't seem to overlap, I'm happy!
How to sew curves - concave clipping, convex notching
That's it!! Neat.

How to sew 2 concave curves

How to sew 2 concave curves


I'll  post example soon. I've made a kurta for my daughter and I'll post the neck which is to attach 2 concave pieces.

How to sew curves - concave clipping, convex notching
 1. P:in the concave fabric right sides together. I sometimes do, most time not.
How to sew curves - concave clipping, convex notching
 2. Sew at the stitching line

How to sew concave curves and how to clip them for a smooth finish
3.  Now clip/cut/slit one of the fabric pieces and then turn and clip/cut/slit in between the intervals on the other fabric piece just like we did for the convex pieces.
How to sew curves - concave clipping, convex notching
 4. Trim to 0.7 cm seam.
How to sew curves - concave clipping, convex notching
 5. Turn right side lightly press with hand.
Spread curves for a smooth finish
 6. Have a look on the inside if they need to spread more. I'm happy here.
How to sew curves - concave clipping, convex notching
That's it!! Give it a good press.
Let me know if this was helpful.

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  1. Very helpful indeed! Thanks for sharing these tips!

  2. Thanks so much! glad you found it helpful.

  3. Excellent tutorial. Great pics especially the Clarity pic for the 2 convex curves! I thought I knew what you meant but the picture proved it.

    1. Thank you! Happy you found it helpful. It has been really easy after I have understood the why's of clipping and notching.

  4. This is perfect! :) What a great explanation - will be pinning! I often forget which one to clip and which curve to notch.

    1. Thanks Deanna. I'd been thinking about it for a week to get it right in my head. It is so easy now. :)

  5. Hi Preethi
    thanks for clearing i thought clip n notch to be one n same u clarified this beautifully with ur this blog thanks a ton


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