I first saw the Churn Dash block as a tiny thumbnail picture in the novel Alias Grace by Margaret Atwood. The block seemed especially simple and traditional then, and I still feel that way today. Like the Bow Tie block, the Churn Dash has subtle elegance. This block can have many personalities, depending on which fabrics you choose.
Step 1 - Cut as follows.
Fabric A: 4.5" x 5" (cut two), 4 7/8" x 4 7/8" (cut two), 4.5" x 4.5"
Fabric B: 4.5" x 5" (cut two), 4 7/8" x 4 7/8" (cut two)
Using a marking pencil, draw diagonal lines on each of your Fabric A 4 7/8" squares. Be sure to align your 45 degree mark with your fabric's edge.
Divide your Fabric A 4.5" x 5" rectangles in half with a marked line. Each rectangle should now have a 2.5" x 4.5" section. Don't cut them!
Match all of your marked Fabric A pieces with your unmarked Fabric B pieces of the same size. Pin them together and sew 1/4" from either side of the marked line. Do this for all pairs of fabric.
After sewing, carefully cut along your marked line between each seam. Do this for all pieces. Press seams open (or however you see fit). You should now have four squares and four rectangles.
Arrange your squares into the proper layout. Admire your work so far.
Starting with the first square, sew squares into rows. Press seams in alternating directions. Then, sew your rows together, taking care to match up seams and points, easing if necessary.
Press final seams whichever way you see fit and iron your block into smooth submission. Presto! Your first Churn Dash.