Gesso Primer and Sealer

What is a Gesso?
with school paints

Gesso school paints
White Gesso
Gesso is a primer, sealer or an undercoat. Artists’sometimes apply it to a surface before painting on it. The word Gesso is Italian for "chalk" or from the Latin ‘gypsum’.

It is normally a white paint mixture consisting of a binder mixed with chalk, gypsum, pigment, or any combination of these. In short it looks a lot like paint but dries to a chalky finish.

The most popular formulation is water based and this is suitable to use as a primer and undercoat for both acrylic and oil based paints. Gesso is the most used medium in all art studios.
Don't use under waterbased tempera poster paint.

Why use a Gesso?
It is used as an undercoat to intensify colours and extend the lasting durability of your work.

Gesso seals absorbent surfaces and it offers the surface a little more texture (tooth), so the paint sticks better. It also helps to prevent uneven appearance and excessive fast drying, resulting from paint penetration. Much like a primer is used under exterior house paint.
But Gesso differs from normal paint primers by making the surface a little stiffer. This is important when painting on a very large canvas that will move about or flap in the wind. Paint sits on top of a surface and if that paint surface is not ridged and secure the paint will crack.

It is used in artwork as a preparation for any number of substrates such as wood panels, canvas and sculpture as a base for paint and other materials that are applied over it.

How to use Gesso:
As with all paintings, surface preparation is everything.
How to use Gesso school paints
Paint thin layers
The lasting quality of your finished painting is only as good as the preparation of the surface and undercoating that you apply underneath the paint.

Even if you have a pre-primed canvas, it is recommended that you still gesso a layer or two.
Stir before use. Gesso can be applied directly from the bottle/jar.

Try to paint thinner rather than thicker. Two or three thin layers are better that one thick coating. Try to work quickly, if you do go back over an area streaks may develop.

Dampening your brush with water before you begin this will help prevent air bubbles forming on the surface.
Keep a ‘wet’ working edge moving as you move across your surface. Try to paint with short even strokes. Normally two to three coats are enough but some artists’ looking for a denser white finish can paint up to six thin layers.

It is important to allow the Gesso to completely dry between layers.

Gesso sanding school paints
Light Sanding between layers
A very light sand with a light grade sand paper between coats may offer better tooth and last ability.

TIP: Try tinting your Gesso. If you are planning to paint a sunset try tinting a white Gesso with a red acrylic to give your painting a ‘pink sunset mood tone’ even before you start to paint. Same thing for a cool feeling to your painting, tint your Gesso with a blue for a cold mood.

Buying Gesso:
Look for a good quality brand as it is better not to take any shortcuts when undercoating for a lasting finish.

Originally, gesso only came in white. Today, gesso comes in many colours. White is still the most popular, but black and other colours are also widely used for folk-art and other art.

Avoid made in China or anything that looks low grade. A good Gesso does not cost much more than the cheap ones and if gives your artwork extra years, then it’s worth it.

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1 comment:

  1. I have found some brands to be too thick and I need to sand between layers. Plus it makes it hard to paint thin layers like you say... Helen Good

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