- A dress shirt -- the bigger the shirt, the bigger the sack. Look for good-quality, heavyweight cotton.
- Fabric for the casing -- sleeves from another shirt work well.
- Nylon cord, 136" long (about 12 ft.)
- Two large grommets
2. Button and pin the front closed.
3. Using a pattern (mine is a rectangle 15 1/2" x 18 1/2"), cut the front and back separately. Be mindful of the front pocket location. Make sure it's at least 2" away from the top edge and 1" from the side edge. Depending on where the front pocket is, you may be able to center the pattern on the front button strip. If there are stripes, try to match them.
4. Sew the button strip closed by stitching on top of the existing seams. Use your machine's zipper foot to sneak by the buttons.
5. Finish the edges of each piece using an overstitch seam (if your machine allows) or a simple straight stitch.
7. To reinforce the bottom of the sack, take the shoulder piece from the shirt and cut a strip as wide as the sack (15 1/2") and about 3" tall. You should have two equal-size strips.
8. With right sides together, sew the strips along the long sides, creating a tube with both short ends open. Turn it right side out and iron flat. Find the center of the strip and pin it to the bottom seam of the right side of the sack. Pin the edges to the sack, and sew the strip to the sack by top-stitching on both edges. (The yellow highlighting shows the seams below).
9. With right sides together, sew the front and back of the sack together at the side seams. Trim the corner (so that it's square when you turn it right-side out).
10. Cut two strips for the casing (my pattern is 15 1/2" x 4") and finish the edges. In this example, I used fabric from my stash, but you can also use the sleeves from another old shirt.
11. Fold over each short edge of the casing 1/4" and iron; repeat, so the edge is folded over twice, then top-stitch.
12. Pin the long edge of one of the casing strips to the top front of the sack, right sides together. Sew. Repeat for the sack back. Iron the seams up toward the top of the bag.
13. Fold the casing in half (wrong sides together), and pin the bottom edge to the folded-up seam of the sack front. Sew the edges together. (If you do this with the right side of the sack-casing toward you, you can insure that the stitch is straight.)
14. Add a large grommet to each bottom corner of the sack.
15. Cut two strips of nylon cord 68" long. Finish off the edges by melting them with a lighter. (Be careful!) Take one cord, pin a large safety pin to the end, and start threading it through one side of casing, then wrap it around and thread it through the other. Pull the cord ends so that they're equal length. Take the other cord and repeat, making sure to start with the opposite end of the casing.
16. Take the two cord ends on one side of the bag, push them through the grommet at the bottom (ends should come through the back side) and tie a knot. Repeat with the other side.
17. Ta da, you're done! See some of the backpacks I've made.