Set of two vintage International Silver Company teaspoons. The International Silver Co. (I.S.Co.) maker’s mark, which is identified by the "I.S.Co. XII", is found on the back of the spoon’s handle. The "XII" marking indicates that the item is silver-plated and refers to the quality of the plating, specifically that twelve spoons were plated with a certain amount of silver. Please see pics. Gorgeous patina.