Today, with the development of high quality plywood and pressed boards, these alternatives are becoming commonly used. . When using paper two areas of concern are the flexibility of the paint media and the lack of acid in the paper itself. Both issues have to be considered. The gesso provides a smooth and white surface on which to gild, draw, and paint . Gesso consists of an inert white agent and glue.
Different recipes go back through the centuries.
Although basically simple, a good gesso is affected by many factors such as humidity, temperature, and of course following the measurements and procedures correctly. There are also companies that make a packaged mixture that requires only adding water and heating. After the gesso is made it is applied in layers. Sanding and scraping is needed to achieve the ivory-like surface desired. It is the gesso that reflects the light to illuminate the pigments on its surface.