Tutorial: How to make HSTs using the Drawn Line Method

Welcome to our first day in our half square triangle series! Today we are tacking the most traditional method for making a half square triangle: The Drawn Line Method.

This is probably nothing new to you seasoned quilters but my hope is that it’s a good resource to newbie quilters!

 Lets get started!

You can trim up your HSTs two ways.  Your option will depend on the size that you originally cut your starting squares so I’ve made a handy-dandy chart to help you figure out what to do.

On the chart below, the first two columns show the finished and unfinished size of your HST.  The finished size is what you will see once you sew the block into your quilt with a quarter-inch seam.

So what do you do?  Find the row with the size block that you want.  If you’re confident in your piecing and cutting skills, use the minimum cutting size column (trimming method #1).  If you’re like me, and you prefer a little wiggle room, cut your original squares to the size listed in column 4 and use trimming method #2.

Trimming option #1 is for starting squares that were cut exactly to size.

Trimming option #2 is used for squares that were cut a little bit larger.  In this example, I’m trimming my HST to 3.5″ unfinished.

Congratulations!  You’ve mastered making a HST using the drawn line method.

As a little bonus for you math lovers like me, I wanted to show you where the numbers on the chart came from.  When we sew a quarter-inch seam from the middle line, we can use the basic 45-45-90 triangle rules to see that we need an extra 1/4*sqrt(2) inches beyond our finished size. That number comes out to just shy of 3/8, but since its so close we call that difference negligible.  That’s why we add 3/8 an inch to our unfinished size to find the minimum cutting requirement.

You certainly don’t need those math skills to quilt but I couldn’t pass up the opportunity to do a little quiltineering!  Just remember to add 3/8″ to your unfinished size and you’ll be good to go!

 

 

Tune in next week when we’ll be tacking the magic method for making half square triangles!