Gesso: what is it?

A term known to creatives and especially painters, gesso is used before painting a canvas. This word deserves closer attention. What is it used for ? How is it made? How to use it and apply it on a canvas?

Gesso has been known for hundreds of years since its first uses date back to the Middle Ages in Italy. At that time, the paintings were often carried out on supports in wood that the artists had to coat to protect them and paint on them more easily. This word comes from the Greek gypsum meaning plaster. It was originally composed of calcium sulphate mineral and animal glue, ingredients that no longer enter into those that constitute it today.

What is gesso used for?

Gesso is a coating used to prepare a canvas, a support in wood, cardboard or even ceramic before painting. Thus, the surfaces will become smoother, limit theabsorption paint that will adhere better to the support. Gesso is also used to create shapes and textures different.

If it is generally white, it can also be black to bring a rougher grain or transparent to conserve the colour of the medium. Gesso today is made from calcium carbonate (essential component of chalk or Meudon white) mixed with a polymer acrylic, a medium latexa pigment opaque white and additives.

How is gesso applied?

If an excellent quality canvas can do without gesso, this coating nevertheless remains the essential basis for preparing a support before painting it. His application is unavoidable in the case of a cotton canvas painted with a oil painting. The latter attacking the support, the gesso will make it waterproof.

It is advisable to apply it with a spalter or a knife in a first thin layer on the support by crossing the strokes of brushes or knife. When dry, the coating should be abraded with a Sandpaper fine, then remove the dust with a cloth. This operation must be repeated once or twice more to obtain a surface ready to paint.