Clean, polished copper gleams, but it only takes a little tarnish to mar that shine, and it can leave copper looking dull and lifeless. More than that, tarnish -- the result of a corrosion process similar to that which causes rust -- can eventually damage copper if it isn't taken care of. Luckily, you can remove tarnish from copper, and applying a coat of lacquer can go a long way in preventing tarnish to begin with.
Wash the copper piece with warm, soapy water using a mild dish soap and a soft cloth or sponge. Opt for dish soaps that are bleach- and fragrance free. Rinse the piece off well to eliminate any residual soap that may have left behind a film.
Dry the piece off thoroughly with a soft, clean, dry towel.
Address areas of tarnish with a paste comprising equal parts table salt and white vinegar. Rub this gently onto the tarnished areas to remove the tarnish, and rinse the area well. Dry the area with a soft, dry towel.
Apply a coat of lacquer to the piece per the manufacturer's instructions for the specific type of lacquer you're using. Work in a well-ventilated area, or outside if the weather permits.
Allow the lacquer to dry completely in a cool, dry place.
Lacquered copper pieces should be washed with warm, soapy water and dried immediately to avoid cracking it.