Criss Kelly, Brocade, graphite, charcoal, pastel, copper leaf on paper.

Applying some gold or metal leaf to your artwork?  Try this from the 15th century, though, I would not recommend it:

“Take clean garlic bulbs, to the volume of two or three porringers, or one; pound them in a mortar, squeeze them through a linen cloth two or three times.  Take this juice, and work up a little white lead and bole with it, as fine as ever you can…And when you want to use any of this mordant, put a little of it into a little glazed dish with a small amount of urine, and stir it up thoroughly with a straw.”         ———-From IL LIBRO DELL’ARTE BY Cennino Cennini, c. 1435