Wheatpaste (also known as potato paste, flour paste, rice paste, Marxist glue, or simply paste) is a liqui adhesive used since ancient times for various arts and crafts such as book binding, decoupage, collage, and papier-mâché. It is also made for the purpose of adhering paper posters to walls and other surfaces (often in graffiti). Closely resembling wallpaper paste, it is made by mixing roughly equal portions of flour and water (some argue using more water or more flour), and heating it until it thickens.