Gives an account of metal thread cleaning carried out by the Crown Suppliers Conservation Studios at Hampton Court Palace. The ca. 1700 Canopy of State from the King's Audience Chamber, covered in crimson damask, with metal braid and tassels, was severely damaged by the 1986 Hampton Court fire; the metal threads were also covered by black corrosion products, which had occurred before the fire. Wet chemical tests were undertaken to analyze small samples of the braid and fringe, with unsatisfactory results. Scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (microprobe) showed the threads to be made from gilded silver wrapped around a silk core. The corrosion products are silver sulfides. Different cleaning methods were tried; they are discussed in terms of risks and benefits; acetone as a solvent seemed to be safer for the silk than water, thus a solution of 2% thiourea and 3% formic acid in acetone was adopted. After treatment SEM and microprobe analysis revealed no damage to the metal and no remaining corrosion. The tensile strength of similar composition silk cores was not affected by soaking in the solution. It is concluded that the method needs to be scaled up to be applicable to the whole canopy, and two lines of inquiry into the prevention of recorrosion are briefly sketched.