Triangle Cutting Question

[Scott Puckett]

I'm trying to cut half- and quarter-square triangles but keep having problems with the 1/4" seam allowance for machine quilting.

Currently, I'm using a 3 1/2" square (3" finished size) as the centerpiece for what I think is called a barn door block and intend for the final block to be 9" x 9".

How can I figure out what the raw size of the triangles needs to be to fit two half-square triangles together to make a finished 3" x 3" piece?

[Lemondrop]

Mathematically, the rule for making half-square triangles is simply this: add 7/8" to the desired finished size of the square, then cut two squares of contrasting fabric with this new measurement. After you have stitched the squares along their diagonals, voila! Two triangles!

To prepare half-square triangles:

1. On the back of the lighter fabric, draw one diagonal line with a pencil or fabric pen. Place the lighter fabric on top of the darker one, right sides together.

2. Using the ¼" machine presser foot as a guide, stitch ¼" away on each side of the drawn line.

3. Cut the squares apart along the drawn diagonal line.


4. Open the two resulting half-square triangles and press toward the darker fabric.

This method works with any desired size half-square triangle. A practice example is a square which finishes at 6 ¾". For example, 6 ¾" + 7/8" = 6 6/8" + 7/8" = 6 13/8" or 7 5/8". Cut two 7 5/8" squares and follow steps 1 through 4 above.


There is an easy way, a software program calledl Triangulations 2.0, see:


www.bearpawproductions.com/triangulations.htm (http://www.bearpawproductions.com/triangulations.htm)


Half square triangle foundations are now available in sizes ½” to 7 ½” in 1/8” increments!
Quarter square triangle foundations have also been added, in sizes 3/4" to 7 ½” in 1/8” increments!



HTH.

[Scott Puckett]

Thank you SO much for the detailed response! Trying to figure this puzzle out has been driving me crazy and I'd like to finish at least one block by this weekend so I can try to turn it into a "quilt" for my fiancee's daughter to use with her Barbies.