In 19th century Europe, the invention of cheap new pigments and dyes made it possible for people to decorate their homes with vibrant hues. But their bold interior designs came with a hidden cost. Pigments such as the wildly popular Scheele's Green and Paris Green were used on everything from children's toys to wallpaper. By 1858 there were about 100 million square miles of Scheele's Green wallpaper in British homes. A scrap of wallpaper the size of a handkerchief could contain a lethal dose of the toxic element arsenic, which gradually powdered down from the walls and released poisonous gas into the room. Despite people knowing that their wallpaper caused deaths, the production was never banned.