Chain stitch is a hand-guided single-thread loop technique. Machine embroidery uses a lockstitch — two threads locked together per stitch. The difference shows after 50 washes.
Durability
Chain stitch fails gracefully: if a thread breaks, the chain unravels from that point but doesn't pull through the garment. Lockstitch can distort the fabric when threads break under tension.
Depth
Chain stitch sits higher off the fabric, creating a three-dimensional effect that catches light at different angles. It's the difference between embroidery that looks applied and embroidery that feels like part of the garment.