Pewter is a metal made of combinations of silvery-white tin, which is the world's fourth most precious metal, and other alloys. Before the 1700s, lead was used with tin to make pewter, but health hazards and tarnishing in pewter objects led to use of other alloys such as antimony and copper. While some pewter owners like to keep their pewter silver-coloured and shiny, many collectors like the patina that darkens the silver colour of antique pewter, and they use different methods to season pewter to give it an aged look without damaging it.
Run warm water in a sink, bucket or dishpan, adding a few drops of dish soap. Clean the pewter carefully with soapy water and a soft cloth. Rinse and dry thoroughly, leaving no trace of water on the pewter object.
Handle the pewter often. According to Danforth Fine Handcrafted Pewter, pewter objects develop a distinctive, warm patina the more they are used. Older pewter that contains lead can form a dark grey or sometimes black patina.
Apply a small amount of pewter polish to items with a soft cotton cloth, rubbing in a circular motion to restore the shine. Using a clean cotton cloth, rub off extra polish and buff the pewter until it shines.
Put on a pair of rubber gloves and turn on a fan. Working in a well-ventilated area, apply a chemical solution known as Pewter Black to your pewter object with a soft, cotton cloth. This solution immediately darkens the pewter. When your item reaches the colour you're aiming for, rinse it and towel dry.
Keep pewter away from heat such as in the dishwasher drying cycle.
Do not use silver polish on pewter.