hi all y make a lot of experimentation with gold on silver and like
the contrast between black patina and gold. y have a probl?e to
conserve patina on my rings.y make black patina with acetate of
copper.or sulfurisation with hyposulfite of sodium with copper
sulfate. y have try a lot of experimentations but patina is very
fragile. is somebody have a solution? maybe a car varnish.