Bell uses ultrasonic welding to make clothes that fold completely flat, like coats with non-fray linings.

The often complex joinings of forces are spelled out in labels where various kinds of handwork mingle with references to 3-D printing, laser this and laser that, ultrasonic welding and custom software-rendered patterns.

Back at the Met, Mr. Bolton called this “silent technology” — the tech you can’t see, like the ultrasonic welding used by Nicolas Ghesquière in a floral dress for Louis Vuitton — and said that for him, it and the collaboration it represents is the future of fashion.

When iFixit CEO Kyle Wiens replied that the goal was to be non-destructive, and asked how they could go further, Luckey responded: "Get really good at ultrasonic welding, maybe! Can't go much further easily, I will give you that."

Do technologies such as laser cutting, ultrasonic welding or 3D printing stand up against intricate embroidery and hand-stitched linings?