Saturday, December 5, 2015

Priming the canvas with gesso (without boiling)

In a previous post, we've talked about stretching the canvas. Today we're talking about priming  the canvas with gesso so you can paint on it just like paper. Priming the canvas is the process of painting the stretched cloth with a substance that makes it more suitable for painting, absorb less oil and colors and prolong its age. The color of the gesso differs according to artists' preferences and the subject of the paintings. It could be brown, black or the popular white. You can find ready canvas in the market but they're expensive and not very good in quality due to the their thin layer of gesso.  Usually gesso is a thick substance made of binder mixed with chalk, gypsum, and pigment. it usually needs to be put on fire for several hour, but today we're gonna use a traditional mixture that an artist family friend taught to me when i was young.
We will need the follwing:
a plastic container with its cover to keep the gesso from drying
a cup of water
3 table spoons of white glue
4 table spoons of zinc powder ( it will give the bright white color to the gesso)
4 table spoons of white lead powder ( it'll give the gesso its solid foundation after it dries)
4 table spoons of paint oil ( flax oil)
a medium size brush
and some cover to protect the surface we're working on from getting dirty
This amount is enough to prime  2 cnavas of 24x 43 size and 2 canvas of 24x 17 size 5 layers of gesso. 
 
put the water and the glue in the container an mix really well so that the glue doesn't leave chunks  on the stretched cloth. After that, add 4 table spoons of zinc and 4 table spoons of while lead and mix till the mixture is similar to thick yogurt.  
Then, add 3 table spoons of oil paint. It will prevent the gesso from absorbing a lot of oil and colors while painting. lay the stretched canvas on the cover and paint the first layer of gesso. Be sure to move the brush vertically and horizontally so the gesso gets into the cloth well. 

Don't forget to paint the sides.
After painting the first layer of gesso , close the container and wait until the it dries (it usually takes from 2 to 3 hours ). repeat the process 5 times to have your canvas ready. 

Notes:
1. the amount of gesso that you need to paint decreases towards the 5 layer.
2. put the canvas in a place where no dust or dirt can stick to gesso while it dries.
3. you can add more layers for a smoother surface ( be sure the brush you use is good)
4. make an amount of gesso that doesn't exceed your need because it turns to a stony substance after a month in the container.
5. if the glue doesn't dissolve entirely in the water, try using a mixer then wash it really good.
6. white lead powder is poisonous substance when it gets inside the body. 
7. Keep the spoon you used with your art stuff for next uses.

Wish you all the best
Ola :)

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