Easy Quarter Square Triangles

What is a Quarter Square Triangle or QST, for short? It’s made of 4, Quarter Squares! 

Another name for this unit is the Hour Glass block.

There is a simple formula used to make them – Finished Size + 1 1/4″.

Finished size = 3″ x 3″. 

3″ + 1 1/4″  =  4 1/4″ x 4 1/4″

Method 1:  Sew First

Step One

1. Cut 2 squares from contrasting fabric using the formula above.
2. Draw a line diagonally from corner to corner on the back of the lighter fabric.
3. Pair squares Right Sides Together (RST). Pin.
4. Stitch a scant ¼” from the drawn line. A scant 1/4″ is a skinny 1/4″, a thread or so less than a regular 1/4″. Do this on both sides of the line.
5. Cut apart on the drawn line and press toward the darker fabric. You have 2 Half-square Triangle units.
6. Clip dog-ears

Step Two

1. Draw a line diagonally from corner to corner on one of the half-square triangle units.
2. Pair the blocks right sides together, nesting the seams.
3. Stitch a scant ¼” from the drawn line. Do this on both sides of the line.

Step Three

1. Cut apart on the drawn line.
2. Press to one side or press seam open.
3. You have two identical Quarter Square Triangle or Hour Glass units.
4. Clip dog-ears.

equals

Method 2: Cut First

This method involves sewing bias edges. Take care with them – they are stretchy! If I’m using this method, I like to starch my fabric before cutting the squares. It gives it more body and is easier for me to handle the bias edges. I like Best Press (TM), Spray Sizing or Spray Starch that you can get in the grocery store. Sometimes I make my own with vodka, distilled water, and essential oil. That’s a topic for another post. Stay tuned!

1. The formula is the same: Add 1 1/4″ to the finished size of the unit.
2. Cut each square diagonally twice from corner to corner.

1. The trick here is to lay the triangles out and sew them so they are identical pairs.
2. Place triangles Right Sides Together (RST) and stitch a scant 1/4″ seam along the SHORT edge. Press to the darker fabric.
3. Make two units.

1. Place two triangle pairs right sides together; the seams should nest. Sew the long edge.
2. Press to one side or press open.

 

Tip

If you prefer to make your units oversized and trim, add 1 1/2″ to the finished size.