After a brief discussion of previous treatments used at the Victoria and Albert to clean metal threads in textiles and the dangers and difficulties of each, the author traces the history of metal threads in Europe and Asia from Exodus up to modern times. She concludes that there are four types of metal filament: 1. Beaten and cut. 2. Cast, drawn and rolled. 3. Leaf applied to gut or leather. 4. Leaf applied to a ground on mulberry paper. Each could be used in its original form or spun on a fiber core to produce a round thread. Using microscopy and energy dispersive x-ray fluorescence spectroscopy, she shows the threads to be various alloys of gold, silver, copper, and zinc. Many are severely corroded. Very careful consideration coupled with thorough microscopic examination must be undertaken before any attempt is made to clean metal filaments. European membranes and Far Eastern paper membranes should never be cleaned; they are simply too fragile. The present policy of the Conservation Department of the Victoria and Albert Museum is not to clean or lacquer any metal filament or thread.