Quarter square triangles are squares made by stitching together four equal triangles. They are sometimes called hourglass blocks.
This method is the most popular for a reason – it is easy and makes two at a time with little waste.
Cutting
You will need two squares of fabric – one light and one dark.
Cut the squares 1-1/2″ larger than the finished size piece you want.
For example, I want my final size to be 4″ when it is pieced in a quilt, so I will cut the squares 5-1/2″.

Marking
On the back of the light square, mark a diagonal line.


Stitching
Place the two squares right sides together and stitch 1/4″ away on both sides of the marked line.

Open and press to the dark side. You will have two half square triangles.

Place right sides together, putting light fabric to dark fabric. The pressed seam allowance will help them stay straight.

On one side, mark a diagonal line.

Stitch 1/4″ away on both sides of the line.

Open and press.
Square up
You will have to square up the finished unit. Because we want the piece to be 4″ square in the quilt, we need it to be 4-1/2″ square with seam allowances.
To square up, align the 45* line of the ruler with the diagonal line. Make sure that the centre intersection of the triangles is 2-1/4″ from the edge of the square.
Trim each of the sides.

You’re done!
You have two perfectly sized quarter square triangle units.

What’s good
- easy to do
- makes 2 at a time
- perfect result
- little waste
What’s not good
- trimming takes time
- have to remember the math
When to use this method
- when you need a lot of QST units
- if you are using pre-cut squares
Rating: 4 out of 5
This method is not difficult to do and it gives a perfect result every time. It’s the most popular method for a reason.

Elizabeth DeCroos
designer, teacher, speaker
Elizabeth enjoys doing all types of sewing and needlework and teaching others new techniques. For more information or to have her speak to your group click HERE.