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Basic Half Square Triangles

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I’m currently working on a really fun half square triangle (HST) quilt!

Which is kind of weird to say because this will be the first standard block quilt I’ve made.

I think I’m doing this quilting thing backwards. My first quilt was a butterfly; all curves with an irregularly shaped border. Then I moved onto appliques. Now I am making basic triangle blocks.

I must admit triangles have been more fun than expected, so today I’m sharing a couple variations of the basic HST method!

Basic Half Square Triangles Technique

Two half square triangle blocks

This first variation results in two identical HSTs.

  1. Start with two squares and place right side together.
Squares of hand dyed fabric and black star fabric

2. Mark the diagonal.

3. Sew ¼” on both sides of the line.

Block with line drawn along diagonal and stitches on both sides

4. Cut along the line resulting in two triangles.

Block cut in half along diagonal

5. Press seam to one side.

Half square triangle block with seam pressed to one side

6. If you made the squares the exact size you needed, trim off the ears.

Ear trimmed off block

If you made your squares a little larger to give yourself some wiggle room, trim the square to size. Line up the diagonal line on your ruler with your seam to make your square perfect!

Measuring along the diagonal

Half Square Triangles – One at a Time

One half square triangle block

Now what if you don’t want two HSTs with the same colors? In my quilt I’m working with hand dyed fabrics, so I wanted to pair up all the triangles individually so I can pick and choose what goes with what. Maybe you’re working on a scrap quilt and don’t want any duplicates. No matter the reason we can modify this method just slightly to make that work! This way you’ll sew just one at a time.

1. Cut along the diagonal of each square.

Two triangles cut from block of fabric

2. Pair two triangles right side together.

3. Sew ¼” away from the diagonal edge. (My fabric is a batik, so that’s why it looks right side up.)

Triangle with seam

4. Press seam to one side.

Half square triangle block with seam pressed to one side

5. Trim same as step 6 above.

There you have it! Now you know how to make one or two HSTs at a time! Do you have a quilt you’re excited to make using HSTs?

Curious how to figure out the math? See how to do the calculations here.

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