Stand out in a sea of canvas backpacks with this rigid, recycled cardboard version that features an unconventional side-lock opening.
- Step 1: Affix the 3½-inch wood strip to the lid with double-sided tape to align with the mark. Use 1¼-inch wood screws to attach the wood strip from the inside of the lid.
- Step 2: Using 1½-inch wood screws, attach the 16¼-inch wood strip to the top and middle holes that were left empty. Then slide the lid under the crossbeam and mark the angle by drawing a 2-inch line along the bottom of the beam in the center of lid.
- Step 3: Attach the strap to the opposite side of the lid, starting in the upper-left corner and wrapping it around the loosened strip one and a half times. Then wrap it over and under the top right wood strip, leaving enough slack for your shoulder.
- Step 4: Remove the bottom screw in the lower left corner and slide the strap underneath the wood between the middle and bottom screws, and then reattach the screw. Pull the strap across and wrap it around the bottom of the right-hand wood strip, leaving enough slack for your other shoulder. Try the backpack on, testing for fit, and then tighten the screws.
- FACT: In one study, six out of 10 American students ages nine to 20 reported chronic back pain related to heavy backpacks.
- Step 5: Flip the backpack upside down and attach the other plywood piece but omit the middle screw. To create the lid, mark excess cardboard at 5½ and 9½ inches and fold. Fold the lid down and mark on each side where it hits the 11-inch wood strips. Cut a ¾ inch strip from there to the end of the lid on each side to allow for proper closure.
- TIP: These screws will be tightened when the strap is put in place.
- TIP: Make sure the corrugation runs parallel to the 16-inch side.
- Step 6: Measure and cut a 16 by 44½-inch rectangle in the cardboard. With the long side closest to you, mark vertical lines at 12, 17½, and 29½ inches from the left edge. Then use a straightedge to fold along the lines.
- Step 7: Stand one of the pieces of plywood on its edge, long side down, and place the 12-inch cardboard section along the bottom left edge of the cardboard, flush with the edge. Place one of the 11-inch wood strips over the cardboard, ½ inch from the ends of the plywood, and secure them with two 1¼ inch wood screws in the center and on the right.
- TIP: Do not attach the third screw in the hole closest to the end of the cardboard. It will be added later.
- Step 8: Turn the plywood onto its short side, pulling the cardboard so it's snug, and center one of the 4½-inch wood strips on top, ½ inch in from the ends of the plywood and screw it in place. Then turn the backpack and attach the second 11-inch strip, using all three screws, but leaving the second and the third slightly loose.
- Step 9: Drill three holes in each of the 11-inch wood strips – one in the center and the others 2 inches in from either end. Then drill two holes in each of the 4½-inch strips, 1¼ inches in from either end.