Wheat paste (also known as flour paste, or simply paste) is a gel or liquid adhesive made from wheat flour or starch and water. It has been used since antiquity for various arts and crafts such as book binding, découpage, collage, papier-mâché, and adhering paper posters and notices to walls. Closely resembling wallpaper paste, a crude wheat flour paste can be made by mixing roughly equal portions of flour and water and heating until the mixture thickens.