Kathy, it’s possible to patina etched copper/silver bi-metal with
liver of sulphur. I learned this method from Carol Webb years ago.
It’s how she achieves that wonderfully graphic contrast in her work.
You’ll need 4 containers. In one make a very very weak solution of
liver of sulphur, the lightest color of yellow you can get (note: it
your liver of sulphur is old, this may take some adjusting). In
another pour some Jax Instant Silver Cleaner. Fill the other 2
containers with cold water.
Dip the well cleaned piece quickly into the diluted liver of sulphur
and then into the first water container to stop the action. Next dip
the piece into the Jax and quickly into the other water container.
This technique relies on speed. Liver of sulphur patinas copper
faster than it does silver, and Jax cleans silver slightly faster
than copper. If it doesn’t work, you can keep doing it, and if it
patinas the silver, then you can dip in the Jax and start over. I
will add that I’ve mostly done this on copper/fine silver, so
results on copper/sterling may vary. Also be sure to use the liquid
liver of sulphur not the powdered variety.
I use Baldwin’s Patina on all my mokume. It does an excellent job
creating a spectrum of colors with different alloys. (No affiiation,
just a happy customer.)
Hope this helps!