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

Jenniffer Eberley says

Lol. Now I know how to use that ruler. 😉

deanne says

Glad I can help!

Becci Havig says

This tutorial on making 8 HST was explained so it was easy to understand. And I never have known how to use this ruler. I wonder if it’s still available. Thank for both.

deanne says

You can find the ruler in quilt shops still and it’s also available here: https://amzn.to/2PPZeoS

Kathy says

Triple DITTO on the comments learning how to use the ruler!

Thank you!!

And I also learned how to be more efficient making half-sq triangle blocks…..

Ingrid says

How do you sew these HSTs together and keep to points?

deanne says

Since there is a 1/4″ seam allowance built into the size of these HSTs, when you stitch them together with an accurate 1/4″ seam, the diagonal seam stays centered and the points remain intact.