An additional wire added to a conventional Fourdrinier papermaking machine, and is a fairly recent development. It makes a twin-wire machine, but with a difference, only one layer of fibre is produced. The top wire is positioned horizontally on the normal wire and the fibre wire is sandwiched between them. It may have either vacuum or foils to assist in the removal of water, which is its main purpose, and 40% of the total water can be removed. The advantages are that the paper produced is more even-sided and the machine speed can be increased.

The hinged wire used in a flip-top earring. Used with a hinge joint and catch. View example.