Making half-square triangles with the Obvious Method

This method of making half square triangle units is the most obvious – cut two triangles and then sew them together on the diagonal.  To non-quilters, it might seem like the only way.  It was probably the first method tried in quilting history.

It is still a great way to make half-square triangles as long as you know what to be careful of.

If you struggle with it, there are other methods that you can use.

See it all

Below you will find:

• video tutorial
• written tutorial with images
• evaluation of this method
• quilt blocks that use half-square triangles
• quilts that use half-square triangles

Tutorial

It seems almost silly to include a tutorial on this method because it is so obvious, but following this tutorial will make your life easier.

Cut strips of fabric

It will be easier to cut the triangles if you start with a strip of fabric the width you need.

The width of the strip will be determined by the ruler that you use.  There are many different triangle-cutting rulers on the market, and I am not an expert.  Ask someone at your local quilt shop and they can certainly explain the differences and point you in the right direction.

This is my ruler.  The numbers on the black lines indicate the size of the finished piece. So you can see that to make 1/2″ finished HST units, you need to cut 1-1/4″ strips.

This makes it a bit easier to do the math.  Also, the point of the triangle is cut off, and that is where the edge of the fabric is lined up.  This helps for alignment and saves extra fabric from the dog ears.

Cut strips into triangles

To cut, place two strip right sides together.  Line up the ruler, and then cut with a rotary cutter.

 After the first triangle is cut, you can turn the ruler around, and cut the next triangle from the point that was left by the first cut.  Don’t separate the fabric pieces, keep them together for sewing.

Stitch

Sew with a 1/4″ seam along the long edge.  In math, that is called the “hypotenuse”.  

This stitching line is on the bias, so treat it gently.  It will stretch out of shape very easily.  Starching before cutting helps.

Press

If you are careful and all the stars are aligned, you will end up with the perfect size square.  In real life, sometimes they will need trimming because they are not exactly right, especially if the stitching line is stretched.

Even if it works out, you might want to trim the dog ears.  I don’t always do that. (GASP!  Don’t tell the quilt police!)

Evaluation of the Most Obvious HST method

pros and cons

When to use this method

• scrappy quilts
• work is careful and precise

Rating: 4 out of 5

I think this method is great for people with some experience or those with the personality to be careful and exact.  For beginners or those who just want to bunches of HSTs without taking care, it might be frustrating.  Cutting, stitching and seam allowances must be exact, but when they are you will get great results.

Quilt Blocks with half-square triangles

Use HST units in these quilt blocks. Click on the links to see tutorials.

Algonquin Charm

---

Pinwheel

Friendship Star

---

Shoo fly

Quilts with half-square triangles

Make these quilts or use them as inspiration for your own.

Fall Nine Patch Sampler

The Nine Patch Sampler Quilt looks great in these scrappy fall colours.

Green Twinkle Sampler

The Twinkle Sampler Quilt is a collection of fun star blocks.

Making Memories baby quilt

This cute baby quilt is the small version of the Making Memories Quilt Pattern.

Rolling Meadows

This quilt is just a collection of half-square triangles. I made it from a kit.