Stitch Length: everything you need to know

When you first start sewing, stitch length is not something you really think about. You just start sewing with the default stitch length, whether that's programmed in a computerised machine, or whatever the dial is set on for a mechanical one.

Is that a bad thing? Probably not! Depending on what you are sewing, it's a good place to start and will work for most beginner projects. But as you sew more, you'll want to vary the length of your stitches, to suit your fabric and the purpose of your stitch. Here's everything you need to know about stitch length:

Everything you need to know about stitch - tips and a guide for choosing the perfect stitch length every time, whether sewing or quilting. Improve your sewing skills for beginners and intermediate sewists. #sewingtips #sewing

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What is stitch length?

Stitch length is basically how long each stitch is sewn by your sewing machine.

Changing the stitch length adjusts the feed dogs, which controls how much fabric is pulled through with each stitch. For a shorter stitch length, less fabric is pulled through. For a longer stitch, more fabric is pulled through.

What do the numbers on stitch length control indicate?

On most modern sewing machines, the stitch length control indicates the length of a single stitch is in millimetres. So a length of 3.0 means each stitch is 3mm long (or just under 1/8"). Stitch lengths typically range from 0 to 5, but can be up to 7, depending on the machine.

Older/vintage sewing machines may show a range of 4-60. No, these machines can't make massively long stitches! This is the number of stitches per inch. Therefore, the bigger the number, the smaller the stitch (and the more stitches that can fit in an inch of sewing).

To convert between stitches per inch and mm, use these simple formulae:

       stitches per inch = 25.4 ÷ stitch length (in mm)

       stitch length (in mm) = 25.4 ÷ stitches per inch 

Why change the length of your stitches?

The stitch length may need to be adjusted for a number of reasons:

  • For basting, a longer stitch is quicker to sew, easier to remove (if required) and easier to use for gathering.
  • For sewing leather or vinyl, a longer stitch to reduces the number of holes punched into the fabric.
  • For top-stitching, a longer stitch length looks more professional (although this is because ready to wear clothing uses a longer stitch as it's faster to sew!)
  • Lightweight and sheer fabrics require a shorter stitch length to prevent pulling and gathering.
  • A longer stitch works better for heavier weight fabrics.
  • A shorter stitch results in a stronger seam, but a shorter stitch can also shred some fabrics! 
  • Thick threads need a longer stitch and finer threads need a shorter stitch.
  • A shorter stitch length is better for smooth curves - a long stitch may make the curve look angular.
  • Don't forget, a shorter stitch is harder to remove. If you're planning on using your seam ripper (ha! is it ever planned??), you don't want stitches that are too small!

How to adjust stitch length

For a basic sewing machine, such as the Janome 10 Stitch, you select the stitch with the appropriate length, and the length is fixed for each stitch.

Janome 10 speed sewing machine

If you have a mechanical sewing machine (ie non-computerized), there is typically a dial on the front of the sewing machine, with either "length" written next to it, or a dashed line, going from short dashes to longer dashes.

Selector for stitch length on a mechanical sewing machine

For a computerized machine, there are either buttons to press to increase and decrease the length of the stitch, or a selection somewhere on the touch screen.

Selector for stitch length on computerized sewing machines

What stitch length should I use?

Here are some guidelines for the best stitch length to use in different situations:

What is the best stitch for: Suggested Stitch Length (mm) Stitches Per Inch
Standard Stitch Length 2.5 - 3.0 8 - 10
Basting stitch 5.0 - 7.0 4 - 5
Stay-stitching 1.5 - 2.0 12 - 8
Top-stitching - light/medium weight 3.0 - 3.5

7 - 8

                     - heavy weight 3.5 - 4.0 6 - 7 
Quilt piecing 1.5 16 - 18
Machine quilting 2.5 - 3.0 8 - 10
Free motion quilting 0 maximum

Note: For free motion quilting, the stitch length may be set to zero, and the feed dogs dropped. The length of the stitching is determined by moving the fabric under the needle by hand.

Note: These are guidelines only. Always test your stitch on a scrap of fabric and adjust to the fabric, thread on your own preference!

What causes uneven stitches?

Uneven stitches can be caused by a number of reasons. Here are some things to check when your stitches don't look even:

  1. Are you pulling the fabric through, rather than letting the feed dogs pull the fabric through? This is a common mistake by beginners. Try not to have your hand behind the needle, forcing the fabric. Let the feed dogs do the work!
  2. If the presser foot pressure is too low, the feed dogs won't get a good grip on the fabric. Increase the presser foot pressure (check your manual for how to do this).
  3. Loose upper thread tension can cause uneven stitching. Check the thread is correctly threaded through the tension disc and increase the tension.
  4. Check the bobbin is threaded correctly.
  5. Change the needle.

Now you know everything about stitch length, watch the quality of your sewing projects improve!

 

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