1. Sew together long edges of brown print rectangles to make 13-1⁄2×20-1⁄2" bag rectangle. Press seam open.
2. Join synthetic leather 1-1⁄2×20-1⁄2" strips to opposite edges of bag rectangle. Finger-press each seam toward fabric center; topstitch 1⁄8" from seam (Diagram 1).
3. Fold bag rectangle in half on seam line; sew together side edges (Diagram 2). Finger-press seams open.
4. To shape flat bottom for bag, at one corner match bottom seam line to side seam line, creating a flattened triangle (Diagram 3). Measuring 2-1⁄8" from point of triangle, draw a 4-1⁄4"-long line across triangle. Sew on drawn line. Trim excess fabric. Repeat with remaining bottom corner to make bag body. Turn bag body right side out and finger-press.
5. Following manufacturer’s instructions, fuse a 10-1⁄2×15-1⁄2" interfacing rectangle to wrong side of each light green print 101⁄2×151⁄2" lining rectangle. The interfacing gives the fabric more body and helps the bag retain its shape.
6. Repeat Step 1 with lining rectangles, leaving a 4" opening in seam, to make a 15-1⁄2×20-1⁄2" pieced lining rectangle. Press seam open.
7. Repeat Step 3 with pieced lining rectangle.
8. Repeat Step 4 to shape bottom corners of lining. Do not turn lining right side out.
9. Insert bag body into lining, right sides together. Sew together around top edge.
10. Turn bag body and lining to right side through opening in lining bottom seam. Topstitch opening closed. Push lining down into bag body and press upper edge of bag from lining side, taking care to avoid synthetic leather. Topstitch 3⁄16" from upper edge through all layers.