Assemble and Finish Bag
1. Using diagonal seams, sew together red-and-black stripe 1-1/2"-wide bias strips to make one long binding strip. Turn under and press a scant 3/8" seam allowance on one long edge.
2. Align raw edge of binding strip with straight edge of bag body piece. Sew together using a scant 3/8" seam allowance. Trim off excess binding strip. Turn folded edge of binding strip over edge to back of bag body (Diagram 2). Hand-stitch folded edge in place with a small slip stitch to bind edge.
3. Repeat Step 2 to bind straight edges of bag side pieces.
4. Referring to Diagram 3, layer bag body and one bag side piece with black novelty print sides together, aligning corners of bag side piece with marked Xs on bag body; pin. Using a scant 3/8" seam allowance and with bag side on top, sew bag side to bag body. Repeat to add remaining bag side.
5. Fold one end of remaining binding strip under 1/2" with wrong side inside; press. Referring to Diagram 4 and using a scant 3/8" seam allowance, sew binding strip to bag body and side. When you reach the opposite side of bag from starting point, trim binding strip 1/2" beyond bag front edge and turn under 1/2". Turn folded edge of binding strip over seam allowances and hand-stitch in place as before.
6. Following the instructions in your sewing machine manual, create a 1"-diameter buttonhole on bag flap using marked buttonhole guide as reference.
7. Stack red and black buttons, and hand-stitch to bag front to complete bag.