1. Referring to Diagram 5, bind 2" end of each bag side with black-and-white print 2-1⁄8x8" strip. Using black-and-white print 2-1⁄8x12" strip, bind the short end of bag body that is farthest from strap tabs.
2. With lining sides together, place a bag side along a bag body long edge; align bound upper edges (Diagram 6). Join long edges, stopping 1⁄4" from bag side short edge. Clip bag body to seam line. Bring bag body up and turn corner; stitch bag body to bottom edge of bag side. Stop 1⁄4" from bag side long edge, bring bag body up and turn corner; stitch bag body to remaining long edge of bag side (Diagram 7). The portion of bag body that extends above bag side will become the flap.
3. Repeat Step 2 to join remaining bag side to remaining long edge of bag body.
4. To create the flap, mark with pins 1" above bag back at both side edges (Diagram 8). Mark 5" from each side edge at free end of flap. Using a pencil and a straight edge, mark lines between pins; cut along marked lines.
5. Starting with bag front, use black-and-white print 2-1⁄2"-wide bias strips to bind all raw edges, mitering binding at corners.