Pink slag is a slag glass that looks like a marble cake. Slag glass appears in different colours. These slag glasses were produced during 1880s. Chocolate glass popularly known as caramel slag, purple slag and blue slag were the most commonly produced slag glass produced during that time. Pink coloured slag glass was produced by Harry Bastow during 1900s in America. Later red slag glass was also produced during 20th century. Slag glass also had another name which is end-of-day glass and due to similarity to marble cake it was also referred as marbled and mosaic glass.