How to Sew Z Seams

Want to design a minimalist quilt? Editing an idea down to its simplest form can be a tricky endeavor. One strategy that may help is to limit the number of seams used during construction. That's easy enough when you're working with straight lines or flowing curves, but what about designs that call for pointy, angular shapes?

 Ruth McDowell's book "Piecing: Expanding the Basics" is a great resource.

Ruth McDowell's book "Piecing: Expanding the Basics" is a great resource.

Enter quilt artist Ruth McDowell. She's been quilting since the 1970s, and many of her works cause quilters to wonder, "How did she piece that?!" Ruth describes her process in several books (which we highly recommend). In Piecing: Expanding the Basics, she explains how to sew a Z seam. You've probably heard of a Y seam, and a Z seam applies the same principles.

Following Ruth's instructions, Kelly Spell tackled the Z seam and brought several examples to our April meeting for her presentation on designing minimalist quilts. Follow these steps to sew your own at home.

How to sew Z seams.png

Some Helpful Hints Before You Begin

  • Make templates to cut your shapes and don't forget to add the seam allowances
  • Use matching thread
  • Shorten your stitch length

Step 1: Mark seam allowances

Do this on the wrong side of both pieces of fabric. There are four points in a Z seam (A, B, C and D), and it helps to mark the entire length of the seam allowance to determine those intersections.

 Step 1: Mark seam allowances to determine intersecting points

Step 1: Mark seam allowances to determine intersecting points

Step 2: Use a pin to align points A & B

Before you sew, you want to align the two pieces of fabric at points A & B, right sides together. Use a pin for accuracy. 

 Step 2: Use a pin to align points A and B

Step 2: Use a pin to align points A and B

Step 3: Sew from point A to point B

When sewing Z seams, you always want to place the piece of fabric with the concave angle on top. (In this example, that means the pink fabric will be on top when sewing from point A to point B, and from point B to point C.) Sew from point A to point B, making sure your needle falls directly into the intersection of the seam allowances at point B. Leave the needle down.

 Step 3: Sew from point A to point B (pink fabric was on top in this example)

Step 3: Sew from point A to point B (pink fabric was on top in this example)

Step 4: Clip, pivot, and align points C

With your needle down, lift your presser foot and clip the concave angle of the top (pink) fabric at point B. You want to clip as close to the needle as possible without clipping your stitch line. Pivot your work and align the two pieces of fabric at point C, using a pin for accuracy.

 Step 4: At your machine, clip the concave angle of the top fabric (pink) and pivot. Then align points C.

Step 4: At your machine, clip the concave angle of the top fabric (pink) and pivot. Then align points C.

Step 5: Sew from point B to point C

When you reach point C, backstitch to secure your stitching and then remove your work from the sewing machine. 

 Step 5: Sew from point B to point C, then backstitch.

Step 5: Sew from point B to point C, then backstitch.

Step 6: Flip your work and align points D

Because the concave angle at point C is on the bottom piece of fabric (the white in this example), you need to flip your work over to continue. Clip the concave angle before you sew, and align the two pieces of fabric at point D. Use a pin for accuracy. 

 Step 6: Remove your work from the sewing machine, flip, and align points D

Step 6: Remove your work from the sewing machine, flip, and align points D

Step 7: Sew from point C to point D

Place the needle directly into the intersection at point C, exactly where you ended your stitching before you flipped your fabric. Sew a few stitches, backstitch to secure them, and then continue to the edge of the fabric just past point D. Backstitch and remove your work from the sewing machine.

 Step 7: Sew from point C to point D.

Step 7: Sew from point C to point D.

Step 8: Press seams

You can press the seams open or to one side, either method will work. If you want to press your seams open you'll need to clip the points. 

 Step 8: Press seams. To press open, clip the points.

Step 8: Press seams. To press open, clip the points.

Ta-dah! You did it!

Sewing a Z seam is a useful skill that may time to master. Give yourself a few practice runs to determine whether you need to make any changes for your particular construction needs. You may find it necessary to reinforce your stitching around points B and C. And if you clip too closely to your stitch line, a member of our guild recommends June Tailor Fray Block.

Happy sewing!

 A completed Z seam

A completed Z seam