An adhesive and paint binder made of the collagen-rich body parts of Elsie, Porky, and Bambi. The same source as gelatine and Jello. Are there vegan Scenic Artists? Aka, "hide glue," as it is made from 72% skin/hide. http://en.wikipedia.org/wiki/Gelatin Sold by the pound in granular or flake form, dissolved in water, and heated over a double boiler known as a glue pot, a benefit (except outdoors) is that the paint is always water-soluble, even when dry, so flats may be washed, sizing re-applied, and painted over again, just like new..