I just love using the chemical "liver of sulfur" to darken my metal. Every time I brush my metal with this chemical its like magic. If this process was done in a factory, the end result would be the same, because the conditions would be monitored for every piece i.e.: the temperature, the amount of water, even the measurement of the chemical. But I am a studio artist, so with every new piece of copper I brush will the liver of sulfur, I feel I am creating a small piece of art. Click on the photo and watch a video of Lisa change the bright color of copper to the beautiful colors of yellow and dark purple.