Half-square triangle squares, also known as HST squares, are a versatile design in quilting. They are used to create blocks and borders. I use them for both in many of my quilt pattern designs. Here’s a pattern where I used HSTs to make the blocks:

Lots of HSTs in this quilt!

I’ve also created many, many borders for my quilts using HST squares. They are often used to make what quilters call a “sawtooth” border. You can find sawtooth borders as far back as the early 19th century when medallion quilts began to emerge as a quilting style of that time.

Here are a few of my designs where I incorporate HST borders:

Here’s a project where I used HSTs to make the blocks *and* the border!

The method I use normally that makes 2 HSTs at once. If I need them to measure 2″ finished when I’m done (2 1/2″ with seam allowance), I start with 2 different color squares each 2 7/8″ x 2 7/8″. If you don’t mind wasting a tiny bit of fabric, you can start with squares that measure 3″ x 3″ so you don’t have to deal with fractions when cutting. Most of you are familiar with this method.

Here are the steps in diagrams: First draw a diagonal line on the wrong side of one of the squares, then lay the two squares on top of each other rights sides together.

Once the squares are stacked one on top of the other, you stitch a scant 1/4″ on each side of the drawn line, cut the unit apart on the drawn line and press each piece open for 2 half-square triangle squares.

Well, you can imagine that if you only make two at a time and you have a lot of HSTs to make…. it could take you a long time to get done!

So, Here is a method to make 8 HSTs at once. You use 2 squares like above, however they need to be twice the size as your finished square + 1 3/4″. For example, if you want 2″ finished HSTs, your starting squares need to be 5 3/4″ ( 2 x 2 = 4″ plus 1 3/4″).

Draw a diagonal line both ways on the wrong side of one of the squares and then lay your squares right sides together one on top of each other just like in the method above. Then stitch a scant 1/4″ on each side of those drawn lines.

Once the stitching is done, cut the square apart as shown.

Next cut the smaller squares apart on the diagonal line:

Next, I like to measure and trim up each HST while they are still closed with the Quilt in a Day Triangle Square-up Ruler. Place the line that shows the size of your HST (with seam allowance) and then trim off the excess.

Now, press open the HSTs and there you go…. 8 HSTs at once!

So give it a try and make lots of HSTs at once!

Let me know if you found this technique tutorial helpful. If you have any ideas for future tutorials you would like me to tackle, let me know in the comments.

Happy Quilting!

Deanne