Another good tutorial can be found at Patchwork-and-Quilting.com.
To find the size to cut your squares, add 1 1/2" to the finished size of the block. I need a 4" finished (already sewn into the block) for the next block, so I cut my squares 5 1/2". Since I need four quarter-square triangles, I cut two light and two dark 5 1/2" squares.
|Two light 5 1/2" squares right sides together on two dark 5 1/2" squares. Draw a diagonal line from corner to corner. Pin in two places so the squares won't shift while you are sewing.|
|Sew a scant 1/4" seam along each side of the drawn line on both pairs. Cut along the diagonal line.|
|Press the seam towards the darker fabric. These are called 'half-square triangles' and we've learned two other ways to make them here and here.|
|Sew a scant 1/4" seam on each side of the drawn line.|
|Cut along the diagonal. The bottom right unit in the photo above shows the seam 'fanned' out to reduce the bulk. You don't have to open the seams this way if you don't want to, you can press the whole seam to one side instead.|
|You can use either a 6 1/2" square ruler (left side of photo) or a Quilt in a Day Triangle Square Up Ruler to square up your blocks. In either case, match the diagonal line on the ruler with the diagonal line on your block and the 4 1/2" marking on the ruler. Trim both sides. Turn the block around so the untrimmed edges are on the top, match up the ruler again, and trim the edges.|
|All four blocks trimmed and ready to be put into the block.|
|My new machine isn't working right now. It's 17 and feeling its age. So I'm using my trusty Featherweight for my blocks! It's tiny and out of the way and so much fun to sew on!|