For modern coins in general circulation, the most common method of protection from forgeries is the use of bi-metallic coins made of two metals of different color, which are difficult to counterfeit at low cost. The most common way of forging these coins is to change the area that should be a different color by painting it; however, the paint is often easy to scratch off and the coins soon look very crude once worn. An increasing number of coins are cast from the same composition alloy as the real coin, but have poor reproduction of details such as the milling on the side of the coin and the stamped lettering.