17th C. Hermetick emblems: Seals of the Philosophers from the Basilica Philosophica (seals of the female alchemists).
The Latin phrase on each is translated in the product name.
Kiln Fired painted Glass with silver stain, copper patina leading and a copper ring attached for hanging.
“Silver stain is a unique pigment. When an oxide of silver is applied to glass and fired in a kiln the heat triggers a chemical reaction coaxing ions of silver to migrate into the glass. The result is that the glass is permanently stained a transparent yellow color. Although the origins of the technique are unclear its impact on the medium of stained glass was revolutionary... The technique was so widely used that the whole medium of “stained glass” obtained its name from the use of silver stain.”
~ Silver Stain: An Artist's Guide, by J. Kenneth Leap