Making half-square triangles with the Strip Piecing Method
Strip piecing half square triangle units is not intuitive, but great if you have strips of fabric to use up. In this method, you can use fabric that would be too narrow to use with most of the other methods.
Every quilter should know multiple techniques for making the popular half-square triangle unit.
This method won’t be used very often, but it’s still good to be familiar with.
See it all
Below you will see:
- video tutorial
- written tutorial with pictures
- evaluation of this method
- quilt blocks with half-squre triangles
- quilts with half-square triangles.
Tutorial
Follow these steps to make perfect triangle units.
Cut fabric strips
Cut fabric strips the same size as the finished piece that you need. For example, if the finished unit will be 4″, then cut 4″ strips, one of each colour.
Stitch
Lay them right sides together and sew a 1/4″ seam on both edges of the strips.
Cut the triangles
Cut triangles using a triangle ruler or the 45ยบ angle line on your basic ruler.
Notice that the edge of the fabric will be the diagonal of the finished square, so it is different than cutting triangles to sew them together.
Open and press
Gently pop out the stitching at the tip of the triangle.
This is where the technique gets problematic. If you have a stitch length that is too short, then you need to be very careful unpicking the stitching or the fabric will pull and distort. If you have a stitch length that is too long, then the ends of the seam might pull loose.
Trim
Trim to size if necessary.
Align the the 45ยบ line from the ruler with the seam line, and trim the edges to the size that you need.
Remember that if you want a finished size of 4″, you need to cut the square 4-1/2″ to allow for a 1/4″ seam allowance.
The triangle units are finished, but treat them gently, as they have bias edges and the tip might be fragile where the stitching was pulled out.
Evaluation of the Strip Piecing HST Method
Pros and Cons
What’s Good
- quick to stitch
- easy for small squares
- great for jelly rolls
What’s Not Good
- accurate cutting can be tricky
- bias edges
- lots of trimming
When to use this method
- you only have narrow scraps left, but need a bunch of HST units
- you want to use jelly rolls
- you are careful with the bias edges
Rating: 2 out of 5
This method is handy if you want to use a jelly roll or some other narrow fabric. Other than that, I wouldn’t recommend it. There are lots of other HST methods, and they are all better than this.
Quilt Blocks with half-square triangles
Use HST units in these quilt blocks. Click on the links to see tutorials.
Quilts with half-square triangles
Make these quilts or use them as inspiration for your own quilt.
Green Nine Patch Sampler
This fun variation of the Nine Patch Sampler Quilt uses the darker fabric as the background. Make your own Nine Patch Sampler Quilt with these free instructions.
No Flies in my Garden
No Flies in my Garden is a beautiful quilt with shoo fly blocks separated by chain blocks.
Scrappy Twinkle
This is a scrappy version of my Twinkle Sampler Quilt.
Scrappy HST Quilt
This is a scrappy quilt I made for my son. It is a collection of triangle units laid out in a light and dark pattern.