Half Square Triangles
Half Square Triangles are a very versatile quilt block. They are used in numerous quilt blocks and can make striking quilts on their own. There are also multiple ways to make HSTs and this post will show you the most common ways to make them.
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Table of Contents
- Paper Pieced
- One at a Time
- Two at a Time
- Skip Drawing the Lines
- Eight at a Time
Paper Pieced Half Square Triangles
I use paper pieced HSTs when I need to make small half square triangles. It allows me to use bigger pieces of fabric and it makes them easier to sew.
I just needed a few half square triangles of each color for this mini quilt that I made so I used Generations Quilts papers. If you need a lot of HSTs I recommend buying the papers per printed from Fat Quarter Shop. They have papers that are designed to use with pre cut fabrics and for specific sizes of HSTs.
HSTs One At a Time
Sometimes you need a variety of triangles and sometimes you need to use up those bonus triangles that are created from snowballing other quilt blocks.
If you are using bonus triangles all you have to do is match the raw edges and sew. There are a few things to keep in mind though. That diagonal edge you are sewing is a bias edge. If you aren’t careful it will stretch and change shape.
When I’m cutting HSTs one at a time I always starch my fabric because of the bias edges I mentioned earlier. Starch helps keep the stretching down but you do still want to be careful when handling that edge.
If I’m cutting triangles I prefer to use an Accuquilt Die. The dies allow me to cut many triangles at once and they let me use up smaller scraps.
If you don’t have an Accuquilt and it isn’t in your budget right now this ruler from Creative Grids is perfect. It has four different ways you can use it so you won’t have a ruler for only one job.
Half Square Triangles Two at a Time
HSTs two at a time is the most common way to make half square triangles. There are some variations to this method though. Some folks use will use strips of fabric but that puts the bias edge on the outside of the block and not in the seam. I do my best to avoid having bias edges on the outside edge of blocks so I don’t use this method.
Instead, I use two squares that you sew on either side of the middle and then you cut down the middle for two units.
In the video above I show you ALL the steps including the math for what size to cut your squares. I don’t like adding 7/8 to my finished size for a couple of reasons. The first is it makes the math complicated if you need something like 4 3/4” for your finished size and if you aren’t the best at sewing 1/4” seam it leaves little wiggle room. I prefer to trim down and waste that fabric than waste a bunch of fabric because I can’t use the finished unit.
If you do want to use the 7/8 but don’t want to do the math I have this handy chart for you.
No Line Half Square Triangles
You can skip drawing lines on the back of your squares by making a jig of sorts. All you need is your quilting ruler, painter’s tape, and a pen. I was watching American Woodshop and he was showing how to make jigs for woodworking. I quickly realized I could use the same theory in sewing.