Gesso is a material used to prepare canvas, linen or other surfaces prior to the application of paint. Once the canvas has been stretched, gesso is painted on, usually two layers thick, to provide a base for the paint. Gesso provides a bright white surface to paint on and prevents the deterioration of the canvas. (Oil paints will rot the canvas if applied directly to it.) It is pronounced like jello, but with s's.

There are two major types of gesso, traditional gesso and acrylic gesso. Traditional gesso is made from marble dust (powdered calcium carbonate), to make the surface white and rabbit skin glue, to adhere the marble dust to the canvas. Traditional gesso was the only way to prime a canvas until the mid 20th century, when acrylic paints and acrylic gesso were developed.

Acrylic gesso is made from an acrylic base and a white pigment. Acrylic gesso is generally similar to white acrylic paint. Acrylic gesso usually has a stronger adhering agent than normal acrylic paint. It also has a higher concentration of whitening pigment (usually titanium dioxide).

The first coat of gesso on a canvas is generally more watery, so that it will soak into the canvas better. The second coat can be thicker, to create a strong base for the paint and to create texture.

Traditional gesso is used by those artists painting oil paintings who wish to paint in a more traditional manner. It does make a base that is a brighter white than acrylic gesso. Traditional gesso is also much more work to prepare and apply than acrylic gesso.

Acrylic gesso can be used for canvases that will be painted on with acrylic or oil paints. It can also be applied to many other surfaces easily. It is easier to apply and work with than traditional gesso.

Gesso, while the name for a preparation for canvas, is also a substance used in gilding. Gilding gesso is made of slaked plaster, white lead (or replacement), organic glue such as fish glue, and sugar. A small amount of colouring can be added to aid in applying the gesso – so it is easy to see where the gesso has been applied.

Once prepared, the gesso can be used immediately, or moulded into small cent sized tablets, which will set extremely hard, and can be mixed with distilled water when required.

When gilding with gesso, it is applied while very wet, and “spooned” onto the surface to be gilded. The aim is to create a puddle of gesso in the shape of the design to be gilded, which, when dry, will be raised above the surface of the paper or vellum.

Gesso allows gilding to be given a very high polish, and the raised surface provided by the gesso allows light to catch the gold.

Gesso is very long lasting when applied properly. Gilding from the great manuscripts such as the Book of Kells was done with gesso, and has in some cases lasted for over a millenium.

Gesso is available from specialty art shops or calligraphy sources. My preferred source (in Australia) is “Will’s Quills” – a mail order calligraphy shop based in Sydney.

Ges"so (?), n. [It., chalk, plaster.]

1.

Plaster of Paris, or gypsum, esp. as prepared for use in painting, or in making bas-reliefs and the like; by extension, a plasterlike or pasty material spread upon a surface to fit it for painting or gilding, or a surface so prepared.

2.

A work of art done in gesso.

[Obs.]

 

© Webster 1913.

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