What Exactly is Gesso?

If you've ever listened to an artist explain about painting with acrylics, in person or on You-Tube, you've most likely heard the term gesso. But what exactly is gesso and why do most acrylic pieces start with a layer of gesso as it base? Gesso is a primer, comprised of binder, chalk/gypsum and pigment. Its purpose is to provide an even painting surface that will better absorb acrylic paints. It is said to have tooth-like properties that help adhere the paint to the surface. Some canvases come already primed, but in most cases, artists will still apply gesso to achieve the surface they desire before applying the acrylic paint. Gesso can be used on most any surface, including plastic, vinyl, wood, etc. Two coats are usually applied, the first to bond with the surface and the second to even it out. Gesso, traditionally white, can be found in other colors and can even be tinted by adding a touch of acrylic paint. It needs at least an hour to dry before painting should begin. Gesso is the generic name for the product and it is available from several manufacturers. Artists, of course, will choose their favorite brand before beginning their work of art.