Sewing Technique: sewing nylon webbing with a box stitch onto the face of a duffel bag. There are different ways to accomplish this step, this is one we've found to be useful
Amazon.com: 656 Yards Heavy Duty Upholstery Thread for Canvas Leather Sewing Repair DIY Craft, 0.6mm Nylon String Extra Strong, 109 Yard/Spool (Black, White, Brown) - Set of 6
Thread bunching on bottom! Only doing it when sewing heavy nylon webbing. Doesn't matter the thread or bobbin or needle (already switched out). Sews fabric fine. Was working fine days ago on
Nylon Hand Sewing Thread - Action Upholstery Supply