Coin clipping was an illegal practice where people shaved away small amounts of silver from coins. People were more likely to clip coins during times of instability, such as when there was inflation or foreign trade was declining. Clipping coins made people distrust the monetary system, which hurt trade. Edward I's long cross penny, issued in 1279, was in part an attempt to combat this – its design reached out to the edge of the coin, making any clipping easier to detect. The long cross and tri pellets in each quarter = London mint.