Brass, an alloy of zinc and copper, has a natural tendency to oxidize over time, leaving it with a tarnished appearance. Although this aged look is sometimes desirable in antique brass collectibles, household items made of brass generally look their best when cleaned, polished and buffed to a high shine. For the best results, use a rubbing compound -- which contains detergents, solvents, mild abrasives and oils, and is available in liquid or solid form -- specifically designed for brass.

• If you’re not sure whether your item is brass or not, test it with a magnet. A magnet will not stick to brass. If the item looks like brass but the magnet sticks, it is probably brass-plated.
• If you can’t move your brass item to a sink, for example when you are polishing a brass surround to a fireplace or a door knocker, clean it using a bucket or dish of hot soapy water. Protect any adjacent wood or plastic parts by covering them with painter’s tape before applying the compound to the brass parts.
• If the brass item is too large or cumbersome to hold in your hands while polishing it, place it on a surface protected with sheets of old newspaper.
• Make your own brass rubbing compound by combining flour, salt and vinegar to form a paste. Smear this over the brass and leave it for a few minutes before rinsing thoroughly.
• If you have heavily tarnished, antique brass that you value, consider taking it to a professional metal polisher instead of tackling the task yourself.