Make Quick Piecing Half Square Triangles

To make quick piecing half square triangles that have 2 right angles many times referred to as half-square triangles, use a grid system or a square.

This method is fast and very accurate.

Because the triangles are not pre-cut, there is less chance of bias edges stretching out of shape.

To determine what size to draw the square, add 1” to the finished size of the triangle (if your triangle finished size needs to be 2”, draw a 3” square). This square size allows for the ¼” seam allowance.

I prefer to add 1" to the finished size of the half square triangle even though many quilters will tell you to add 7/8". For me, the even 1" is just easier to cut.

You will have a little bit of extra fabric but I like to allow for a little room for error. As you become more familiar with this method, you can decrease your "extra allowance" down to 1/2".

Cut a 3” square from two different fabrics.

Place two different colored fabric squares, right sides together with the lightest colored (or easiest to mark) fabric on the top. With a very sharp pencil, fine point pen or other pointed marking pencil and a plastic ruler, draw a line from one corner to the opposite corner.

Cut the triangles apart on the drawn line.

A rotary cutter, ruler and mat speed up this process for quick and easy machine piecing.

However, the square can also be cut apart with scissors.

Use the cutting tools that will help you be the most accurate.

Trim to be an accurate 2 1/2” square (or the correct size for your quilting project).

Be sure to line up the 45 degree diagonal line on the ruler with the seam of the triangles.

This gives the most accuracy.

If you need more than 2 quick half square triangles you can use a grid with more squares. Remember that each square drawn on the grid will yield two half-square triangles. Ex: a three square x four square grid yields 24 half-square triangles. Mark the 3" grid on the light fabric. Draw a diagonal line in each square to form the stitching and cutting line. Stitch 1/4" seam allowance on each side of the stitching line. Proceed as above.

This is a great quick and easy rotary cutting technique for easy machine piecing particularly when working on quilt project.

Go to Easy Machine Piecing from Quick Piecing Half Square Triangles