One of the first patinas I learned was fuming copper in a closed container with ammonia. The ammonia fumes created a blue-black color. Not beautiful in and of itself, but at the conservator's suggestion at the Freer Gallery in Washington, DC, I use an old Windex bottle to spray uric acid on the tea bowl. Viola! The uric acid turned my dusty blue-black patina a beautiful, permanently mottled chromate green. The same conservator showed me how to apply low karat gold leaf in a wispy fashion that appeared like a brushstroke to accent the green patina.
Recycled materials, woven copper, chemical patina, polychrome 6" x 6.5" x 6".