Cut four 3.5" squares out of your background (light) fabric.
Cut four 3.5" squares out of your main fabric.
Once again, these are larger than they need to be because I like to be safe and cut the block to size later. Theoretically they only need to be 2.75".
Make eight "half square triangles" as follows:
On the wrong side of each light square, draw a diagonal line from one corner to the opposite.
Put a light square on top of a dark square, right sides together, and sew a ¼" seam on each side of the drawn line.
Cut the square in half along the drawn line. Open and press the seams towards the dark fabric.
If you do this for each pair of squares, you will have 8 half square triangles.
Just for the record, I have no idea why they're called this, since they're squares, so in my opinion they should be called "half square squares".
Lay them out in a pinwheel pattern as follows.
Make two pinwheel blocks like this one.
Trace the center circle from the diagram or print the block from the CD onto the dull edge of freezer paper. Make sure you mark the center of the circle. Cut out. Position the freezer paper circle in the center of one of your pinwheel blocks (on the right side) and, using a dry iron, iron the freezer paper onto the block.
Cut out, remembering to leave an 1/8" to 1/4" seam allowance.
Carefully position the circle on the remaining pinwheel square, turning it 45 degrees so that each dark section lines up with a light section on the square.
Match the seams carefully and baste.
To reduce bulk and make the circle lie down flat, I cut a section out of the back of the square.
Using the needle turn applique method described in block A-7, applique the circle onto the square. Keep checking as you go to make sure your seams still line up.
Press your completed block and trim it to 5" making sure the circle in is the center.
I also trimmed away some more of the bulk in the back at this point.
I think this is my favorite block so far.
P.S. If you want to piece curves, you can make pattern pieces and piece the block as described in B-3.