CECILIA WELDEN is an artist living in the Bay Area. Using mild acids she draws images of buildings on copper-wrapped birch panels. The images are made by temporarily sealing the background areas with an acid resist. The areas left exposed from the acid resist are then darkened with a chemical patina. This “blocking-out” method is similar to a batik or printmaking process.
Patina is a mildly acidic solution that darkens the copper. Once the desired color is reached with the patina, the copper drawing is neutralized to prevent further darkening. The copper is completely cleaned and neutralized again. Next it is sealed with several coats of an industrial metal outdoor sealant to prevent the copper from further darkening and reacting. The patina will not fade nor will it further react.