Gouache tubes and a "Chinese white" tube was added to boxes for this purpose. Later that century, for decorative uses "poster paint" was mass-produced, based on the much cheaper dextrin binder. It was sold in cans or as a powder to be mixed with water. The dextrin replaced older paint types based on hide glue or size. During the twentieth century, gouache began to be specially manufactured in tubes for more refined artistic purposes. Initially, gum arabic was used as a binder but soon cheaper brands were based on dextrin, as is most paint for children. A relatively new variation in
Gum arabic that "based on present scientific knowledge only an arbitrary value can be used for regulatory purposes". In 2008 the FDA sent a letter of no objection in response to an application to reduce the rated caloric value of gum arabic to 1.7 kcal/g. Gum arabic is used as a binder for watercolor painting because it dissolves easily in water. Pigment of any color is suspended within the acacia gum in varying amounts, resulting in watercolor paint. Water acts as a vehicle or a diluent to thin the watercolor paint and helps to transfer the paint to a surface such as