The zip fastener was first invented for fastening shoes by the American inventor Whitcomb Judson (d 1909) in 1891. This example is an early French design. The zip fastener has two sets of interlocking teeth, meshed by means of a slide that moves up and down. The slide contains wedges that detach the teeth and force them apart when opening the zip and also push the teeth together when the zip is being closed.
© Science Museum / Science & Society Picture Library