A few weeks ago, I did a post on half-square triangle (HST) squares which included instructions on making multiples of these units. Those unit have a bias seam. Another type of unit that has a bias seam are those created using the technique referred to at stitch & flip or folded corners. That’s the type of unit I will cover in this week’s piecing tips, along with basic fabric facts to keep in mind while cutting and piecing your current project. So let’s get started!

Fabric Grain & Bias

To understand the difference between a bias (diagonal) seam and a straight seam and why they behave differently, you need to know about fabric grain and bias. This may be a review for experienced sewers and quilters, but it never hurts to review.

The lengthwise grain of the fabric runs parallel to the selvage and is the most stable grain of the fabric.

The line I’m pointing to in the left photo is showing the lengthwise grain. In the second photo, notice how there’s not much stretch to the fabric when I pull on opposite sides of the piece of fabric. It’s a good idea to cut in this direction for long pieces needed for the project like border strips, if possible.

The crosswise grain is a little less stable than the lengthwise grain. It’s perpendicular to the selvage (the line my finger is pointing to). As you can see in the photo below, there is a little more stretch to the fabric in this direction.

Finally, the bias of the fabric is at the 45 degree angle from the selvage. This is where the fabric is the least stable.

It’s important to remember this because any seams that are diagonal are in the bias direction of the fabric. Any seam sewn on the bias (like in HSTs) must be handled with care when pressing or ripping out so the fabric is not stretched out of shape. Once fabric is stretched a lot on the bias, it can remain distorted.

Bias Seam Type – Flying Geese

Since we covered HSTs that have a bias seam in a previous post, I’ll move on to another unit that has bias seams – flying geese. This is an example of the stitch & flip technique. I think most of you are familiar with how to make the traditional flying geese unit, but I will review quickly below.

Using 2 squares 2 1/2″ x 2 1/2″ and a 2 1/2 x 4 1/2″ rectangle, the photos below show the steps:

Draw a diagonal line on the wrong side of the two squares. When you lay one of the squares face down on the rectangle, pin to keep the square from shifting. Once you sew along the line, the next steps (photos below) are very important:

On the left I am folding over the square, after stitching the seam, to make sure its edge matches up with the edge of the rectangle. The center photo shows that when I measure the unit, it still measures 2 1/2 x 4 1/2″ . I can then trim off the excess fabric in the seam allowance (last photo). That is a key in stitch & flip units, always fold over and measure the unit after stitching before trimming off any excess fabric. 

Repeat the above steps on the other side, and you will have a flying geese unit. For making multiple units at once, see a previous post of mine here.

Bias Seam Type – Other Stitch & Flips

There are other ways to use the stitch & flip method besides making flying geese. Stitch & flip is also used to make corners on squares that add a unique look to the design of a block. The block shown below is from my Star Wheels quilt. It has flying geese in it, but also other stitch & flip parts:

I also used stitch & flip in my quilt Sunset Sky:

Besides the flying geese units that make up the center star of that block, the four corner squares have a lot of stitch & flip!

You can do stitch and flip on any block unit that has a 90 degree angle like a square or a rectangle. I’m going to demo using the black pointed units in Star Wheels block from above. The steps are similar to making single flying geese units.

In my demo, I start with a 2 1/2″ black square and a tan 1 1/2″ square. Draw a line on the wrong side of the tan square as a guide for stitching, lay the smaller square face down on the larger one and line up its edges with the edges of the larger square as shown. I like to pin it in place for stitching so the small square does not shift. Then stitch on the line.

Once the seam is sewn, I fold over the square like I did in the flying geese steps above and measure the unit to make sure it still measures 2 1/2 x 2 1/2″ and the edge of the small square lines up with the edge of the larger square. Then I can cut off the excess fabric in the seam allowance (last photo below).

Repeat these steps on the other side of the square to finish that unit:

Here are some other blocks that I’ve made using the stitch & flip technique:

You can create a lot of interesting designs using this method. Just be careful if you have to un-sew any of these bias seams. Like I mentioned earlier, the fabric stretches easier on the bias and you could end up distorting your block pieces. Once you cut away the excess fabric in the seam allowance, you can’t un-sew the unit and start over. That’s the reason why I have you measure the size of your finished unit prior to cutting any excess seam allowance away. 

See my mini video tutorial where I demonstrate stitch & flip steps below:

So that’s it for this week. Leave me a comment or ask questions below and I will enter you into a drawing for my quilt pattern for Sunset Sky. The drawing will be on Monday, February 26th. Good luck!

Happy Quilting!
Deanne