The next project and demonstrations focused on techniques used to add a patina to copper. A patina is the coloration that occurs on metals, and in this case on copper, when it is exposed to various chemicals processes and oxidation.
Harlan introduced us to a number of ways to add a patina to metal. There is even a book, Patina:300+ Coloration Effects for Jewelrs & Metalsmiths, housing a whole bunch of formulas that can be used to produce different effects.
The top leaf was produced by a chemical formula from the above mentioned book. I did not actually mix the chemicals and cannot remember what went into it. However, once the chemicals were mixed, they made a thick paste which was applied to the hot copper leaf (it had been boiled in hot water) and allowed to sit for 24 hours before washing the paste off and sealing.
Another patina which turns copper truly beautiful, is a heat patina in which the copper is rubbed with peanut oil and is then heated to create varying orange hues.