Monk as the last step in sanding enamels to clean out the left over glass dust on the piece we place in the ultrasonic before the last flash firing in the kiln to keep the enamels clean so the contamination doesn't get mixed into the final firing.
I generally feel copper is softer than brass or bronze in the hardened state or when all are annealed. And generally hardened or annealed bronze is harder than hardened or annealed copper and brass. But then again the alloys in the metals can change all this, and that could make all the...
Dulling Glaring Distracting Reflective Surfaces when Photographing
I discovered using a little dab of Sam's Transfer Wax along the surface does the trick
Hardness of Metals Chart
https://www.sccboe.org/cms/lib/AL50000450/Centricity/Domain/779/the-hardness-of-metals-a-visual-representation-of-the-mohs-scale.pdf