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Half Square Triangle 2 ways

image of a HST

We are exploring essential quilting techniques that form the foundation of quilt-making. Whether you are a novice or a seasoned quilter, we hope to share inspiration and education. Each month in 2024, we are sharing various techniques you can use when writing your quilt patterns. We are going to provide standard wording for steps and show you illustrations you can use in Adobe.

Half Square Triangles (HST) are probably the first skill a quilter will learn. It is the most-used block in quilting and can be made in several different methods. This month we are discussing the two most popular methods of making HSTs: 2-at-a-time and 8-at-a-time. Depending on the pattern, you can make as few or as many HSTs as you need and do it as efficiently as possible. An entire quilt can be made only with HSTs and can have completely different looks based on how the HSTs are assembled.

Images from Sew Can She HST blog post

2-at-a-time Half Square Triangle method

This is probably the easiest method to use for a scrappy quilt. You can make as many different HSTs as you would like for your project in a bunch of different fabrics. To get the appropriate size, take your finished HST (as it will be in the quilt when it's done) and add 1". So if you want a finished 3" x 3" HST, cut your squares at 4" x 4". Such a simple formula to remember! And you will even have a little excess so you can trim them to the correct size.

  1. Draw a diagonal line, corner to corner, on the wrong side of the lighter-colored square.

  2. Place the (2) squares RST.

  3. Sew 1/4" on each side of the drawn line.

  4. Cut on the drawn line to create (2) HST.

  5. Press toward the darker fabric or press open.

  6. Trim each HST to the desired size.

Many quilters just keep sewing HSTs square by square, even chain piecing. Then they head over to do all the cutting and pressing and, lastly, the trimming in an assembly line fashion. They say it makes them "get in the zone".

diagrams for the 2 at a time HST

8-at-a-time Half Square Triangle method

If you are making several HSTs in the same color, making them in batches is a huge time-saver as well as getting them very accurate. This formula is also easy to remember (my favorite kind!). Take your finished HST size, multiply it by 2, then add 2". That gives you just a little excess so you can trim to size and not be skimpy. So if you need that 3"x 3" finished HST in your quilt, take 3 * 2 (=6) and add 2" (=8"). You will cut your squares at 8" x 8".

  1. Draw (2) diagonal lines, corner to corner, on the wrong side of the square, creating a large X shape on the square.

  2. Place squares RST.

  3. Sew a 1/4" on both sides of each of the drawn lines (for a total of 4 seams).

  4. Cut along each of the drawn diagonal lines, and then again along the vertical center and horizontal center of the square. This makes (8) total HSTs at a time.

  5. Open and press seams to the darker fabric.

  6. Trim each HST to the desired size.

step diagrams for the 8a t a time HST

We hope this helps when writing your next pattern. Having piecing steps in your pattern library will make the process of writing more efficient and less stressful. If you have any questions or suggestions, drop us a note. We would love to hear from you.

Happy Quilting!

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