2. Starting from the card position, positioning, punching and sewing.

3. The inner layer is assembled and ready to be stitched with the outer layer.

4. Make a hole before sewing, and then sew by hand with double stitches. H Maersk uses this sewing method, which is characterized by being very firm. Even if one thread is broken, the bag will not fall off. Sewing is the most time-consuming!