In this video, you'll use three stitches to sew a backstay to a blocker. The backstay is already bar-tacked to the blocker material on one end. You'll stitch the backstay to the triangle on the front side of the blocker.
There's a V-notch on each leg. To sew the backstay onto the blocker, you'll first position the right leg over the right line of the triangle. Center the V-notch with the line, keeping it even with the edge of the blocker. Then slide it to overhang the edge of the blocker a quarter inch.
Now you'll use your straight line stitch that you practiced earlier. Line up the outside edge with the edge of the presser foot. As you stitch, keep the leg centered over the line. Be aware of where your fingers are as you sew. Make sure to hold the backstay tab to keep it squared. Continue stitching until you are even with the drawn line on the blocker.
This is where you'll use the 90-degree corner stitches. The left needle stitches should be lined up with the drawn line. Be careful not to run off the edge of the backstay. After stitching two or three stitches down the other leg, stop and center the leg over the line. Continue stitching the rest of the way down and off the backstay.
Now, turn the leather to stitch the inside of the backstay. This is where you'll use the tree stitch. Stitch to the triangle point, then take three more stitches, make your turn, and stitch to the end. Let the finished blocker hang.
On the next blocker, center the V-notch of the right leg over right line of the triangle. Then, slide it to overhang the edge of the blocker a quarter inch. As you stitch, keep the leg centered over the line. You will also need to hold the backstay tab to keep it squared.
Make your 90-degree corner. Stop at the second corner, and cut off the hanging blocker. Inspect the stitches, and trim the overhanging edges so they're even with the blocker. Make your turn, and continue stitching, making sure the leg stays centered over the line.
When you get to the end, turn the leather to stitch the inside of the backstay. Stitch up to the triangle point, and take three more stitches, make your turn, and stitch to the end. Sew off of the backstay and let it hang.
When you're finished stitching the backstay blockers, sew onto a piece of scrap leather. Remember to trim the finished blockers and inspect the stitches.