How to Sew Curves without Puckering

This tutorial will show you how to sew curves in fabric, including concave, convex, and opposing curved seams. Sewing curves incorrectly will result in puckered seams and a rough-looking garment or project. Here you’ll learn how to sew curved seams on a sewing machine step by step, with simple tips that even beginners learning how to sew can follow.

To sew curves, use a shorter stitch length, sew slowly, and guide the fabric without stretching it. Clip or notch the seam allowance after stitching so the curve can spread and lie flat. Press the seam well to remove puckers and bulk.

How to Sew a Curve in Fabric (Concave, Convex and Opposing

Learning to sew curves is part of sewing 101. It is a beginner skill that you will use constantly. The key to sewing a curve on a sewing machine is clipping the seams, so they don’t pucker. How they are clipped depends on the type of curve. After sewing curved seams, you may need to clip the seam allowance. Learn more in my tutorial on how to clip corners and curves.

If you are learning beginner sewing techniques, read the full how to sew a seam guide to improve seam accuracy and sewing control.

Here I will discuss 3 ways to sew curves:

1. Sewing Concave Curves
2. Sewing Convex Curves
3. How to Sew Opposing Seams

Curved Seams Quick Chart:

Curve Type	Where You See It	How to Clip	Key Tip
Convex (outward)	Pocket flaps, bag curves	Notch (cut triangles out)	Trim bulk before turning
Concave (inward)	Necklines, armholes	Clip (snip into seam)	Stop snips before stitches
Opposing curves	Sleeves, quilt pieces	Clip (release tension)	Pin center + ends first

How to Sew Curves that are Convex

A convex curve is simply a curve that faces outwards, much like a circle. It can be commonly found on pocket edges, clutches, and bag flaps.

1. Mark Seam

Draw the seam allowance line using a removable fabric marker or tailor’s chalk. This gives you something to follow when sewing and will increase your accuracy. Without a line to follow, it can be hard to visualize the curved seam line and predict when to turn.

The easiest way is to mark from the edge with a seam gauge or ruler in little dashes and then join them up.

2. Sewing Curves Instructions

To stitch on a curve, your fabric pieces right sides together and pin.

Place your pins vertically so that you can follow the curves with minimum interference. You will need more pins than you normally do for straight seams. Place the heads on the outside of the curve, so they are easy to remove as you go along.

Stitch the seam. The best way to sew curves is to set your machine to a smaller stitch length. Try a length of 2.0-2.5. Stitch slowly and gently guide the fabric with your fingertips. If you are new at sewing, read all about how to use a sewing machine to make sure you have the right settings for your fabric.

Keep your eyes on the marked seam line in the front.

• For gentle sewing curves, you should be able to stitch in one motion without stopping.
• For tight curves, you may need to stop with the needle down in the fabric, lift the presser foot, pivot the fabric, and start stitching again. Make multiple small adjustments rather than one large adjustment to maintain a smooth curve. This will also stop the fabric from wrinkling up and catching on your presser foot.

If the curve stitching is really tricky, you could sew the hardest part by turning the hand wheel for maximum control.

3. Clipping

Once you have sewn your curves, you will need to clip the curves to remove some of the excess fabric to maintain the curve’s smoothness when turned right side out. For convex curves, cut triangular notches out of the seam allowance.

4. Turn & Press

Turn the right way out and give your curves a good press.

Sewing Curves that are Concave

A concave curve faces inwards and can be commonly found on necklines and armholes of garments. Here are the instructions for stitching curves that are hollow:

1. You will sew it the same way as a convex curve, with the only difference being the way you clip the seam allowance. Instead of clipping notches, you can just make little snips ending just before your stitching line.

2. Give it a good press, and here is how it looks.

How to Opposing Sew Curved Seams

So what do we do when we have 2 curves facing in opposite directions? You will often see this in quilting patterns or in garments with color-blocked segments. You will also use this technique when sewing sleeves to armholes.

1. Add Seam Allowance

If your pattern doesn’t already have a seam allowance added, then now is the time to add it. If you add smaller 1/4 inch (6mm) seams, it makes it easier to sew the curved edges together.

2. Mark Centers

Mark the center of the pieces and pin them right sides together. See how the rest of the curves are now facing opposite directions?

3. Ease and Pin

Match and pin the ends of your pieces and then work the in-between sections together. Place your pins vertically to hold the fabric in place and out of the way. The greater the curve, the more pins you will need.

4. Sewing Curves Together

Now stitch along the seam with your seam allowance. It is easier to stitch from the top curved piece. Run your finger underneath regularly as you sew to make sure nothing is caught up underneath.

5. Clipping

Clip the seam allowance to release tension.

6. Press

Open up your piece and give it a good press. This will make all the difference.

The seam allowances should both be pressed to the one side. It will naturally go in one direction. Don’t try and press the seam allowances open, as it is generally too difficult.

And there you have a nice color-blocked piece. Now you know how to sew curves, you could actually make more curved pieces and turn them into a quilt!

How to Sew Curved Hems

Curved hems are best sewn with a Narrow Hem.

How to Sew Curves Without Puckering

No matter whether you are stitching gentle necklines or piecing together opposing seams, sewing curves requires control and precision. Read through these tips to get professional results every time.

1. Mark before you sew with a removable marker or chalk.
2. Pin carefully, keeping the pins vertically and close together. If the pinheads are on the outside, they are easier to remove. While sewing curves without pins is possible, using them will give better results.
3. Adjust your stitching to a smaller length of 2.0-2.5 so you have better control.
4. Sew slowly while looking at the seam line and not the needle.
5. Remember to clip afterwards before you turn your article. Convex curves need small triangles, and concave curves need snips. Don’t cut the seam!
6. Finally, press for perfection!

Common Problems When Sewing Curves and How to Fix Them

The most common mistake I make when sewing curves is to not clip enough and this results in a puckered seam. Really take your time with that, but of course, don’t clip the stitching! Of course don’t forget how to use a seam ripper to fix anything that goes wrong. Here are some other common reasons your curves may not look right:

• Fabric puckers → Not clipped enough
• Wavy seams → Stitches too long
• Jagged curves → Sewed too fast
• Bulk → Seam allowance too wide

Sewing Curves by Hand

You can use the same techniques I have outlined above when sewing curves by hand. You are best to use a backstitch in a very small stitch length. Be extra careful when clipping, not to cut the seam, as hand stitches are more likely to unravel.

Pin for Later

Sewing Curves FAQs

In Conclusion

Learning how to sew curves is an important beginner sewing skill that will improve the look and fit of your projects. Whether you are sewing convex curves, concave curves, or opposing curved seams, the key steps are to sew slowly, use a shorter stitch length, and clip or notch the seam allowance so the fabric lies flat. With a little practice, curved seams will become just as easy to sew as straight seams.