Cleaning antique brass and copper
Antique brass and copper don't always have to be cleaned or polished but as with any metal, exposure to air causes the surface to oxidise and tarnish, at which time the colour can change to brown or greenish black.
Hallmark Copper Brass is an extra strong polish product.
Les anciens ebenistes offers Désoxydant and Brillanteur, products that will make your brass and copper shine again.
It's useful to know whether your brass piece is plated or solid, because obviously a plated piece can and very often does wear through to reveal the base metal. Cleaning, then, can often make matters worse. It's easy to test using a small magnet. If the magnet sticks, the object is plated, if not, it's solid brass or copper