Hi!
I’m a metal detectorist. Black wound badges are somehow almost common find for me. Some are quite good, some are poor especially iron ones. I was almost piling them up in a box, and some I really didn’t hurry to clean. Not long ago, I found hollow backed WB, made from copper and it showed clear remains of silver plating. Later I also read article about cleaning bronze and copper with olive oil and decided to give it a try on other black copper base WB’s. It turned out, that 2 of them are in fact copper made, but were later gold plated and then painted black.
The black paint was in fact hiding gold plating, and remaining surface was oxidized and verdigris copper. Mostly I read that black WB’s were hollow-back but silver & gold were fully cast. Sure there can be some exception to that. But why would someone paint fine gold medal in black?

1.silver plated, never showed black color
2.gold plated, looked entirely copper verdigris and black painted
3.spots of gold were visible before the cleaning, but the back was entirely black painted
1st click enlarges to window, 2nd click enlarges to actual size of a photo.
And that brings me to another medal painting question, maybe I already posted it on this forum years ago. Here is a pic of KVK2nd class, all edges on right side show clear remains of black color. In fact, the tip of one sword is much better preserved because of the paint. Any idea why to paint KVK 2 in black ?