Strong, soil-resistant Whitman albums with blue textured leatherette cover are designed with thumb notches for easy window removal. Through the years, Lincoln cents have seen changes in their composition and design. The reverse of the coin has gone from the emblematic Wheat Ears to the current symbolic Shield. Their composition has seen three main stages: 1909-1942 and 1944-1982 coins were made mainly of copper; 1943 coins were made of zinc-coated steel and some of bronze and silver; 1982 to Date coins are made primarily of copper-plated zinc. Lincoln cents coins measure 19 mm in diameter and their weight has varied depending on their composition. Early year coins, for example, weigh 3.11 grams, cents from 1943 weigh 2.70 grams, and the ones now in circulation weigh 2.50 grams.