Pewter is a malleable alloy comprising mainly tin and was in common use in Roman times. The composition of pewter can vary depending on its intended use.
Typical composition of pewter tends to be in the range of 74 to 89 per cent tin, 0 to 20 per cent lead, 0 to 7.6 per cent antimony, 0 to 3.5 per cent copper with trace levels of zinc. Arsenic and iron may also be present as impurities.
Traditional pewters came in a range of alloys. First grade -- "fine" -- pewter was tin with 1 per cent copper, used for flatware. Second grade -- "trifle" -- pewter was fine grade mixed with 4 per cent lead, for items like cups and bowls. "Lay" metal (third grade), for non-food and drink uses, was tin with 15 per cent lead.
International standards define pewter as having a composition of 90 to 98 per cent tin, 1 to 8 per cent antimony and 0.25 to 3 per cent copper, with limits specified for various impurities (lead, arsenic, iron and zinc).