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
- Cut 2 squares from contrasting fabric using the formula above.
- Draw a line diagonally from corner to corner on the back of the lighter fabric.
- Pair squares Right Sides Together (RST). Pin.
- 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.
- Cut apart on the drawn line and press toward the darker fabric. You have 2 Half-square Triangle units.
- Clip dog-ears
- Draw a line diagonally from corner to corner on one of the half-square triangle units.
- Pair the blocks right sides together, nesting the seams.
- Stitch a scant ¼” from the drawn line. Do this on both sides of the line.
- Cut apart on the drawn line.
- Press to one side or press seam open.
- You have two identical Quarter Square Triangle or Hour Glass units.
- Clip dog-ears.
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!
- The formula is the same: Add 1 1/4″ to the finished size of the unit.
- Cut each square diagonally twice from corner to corner.
- The trick here is to lay the triangles out and sew them so they are identical pairs.
- Place triangles Right Sides Together (RST) and stitch a scant 1/4″ seam along the SHORT edge. Press to the darker fabric.
- Make two units.
- Place two triangle pairs right sides together; the seams should nest. Sew the long edge.
- Press to one side or press open.
If you prefer to make your units oversized and trim, add 1 1/2″ to the finished size.