Acrylics, Oil Paint, Painting

What Does Fat Over Lean Mean?

August 19, 2014

By Alina Bradford

In oil painting, new artists are told to paint “fat over lean,” but what does this really mean?

impastoFat over lean, thin under thick and thinnest to thickest are all ways of saying the same thing in oil painting; make the painting dry properly by using the right consistency of paint at the right time. Using this concept, an artist can make their painting more stable and long-lasting. So how does an artist go about painting fat over lean? The process is actually quite simple.

The Fat Over Lean Painting Process

To paint fat over lean, the artist simply uses their thinnest paint mixture for the first layer of the painting. Each consecutive layer should be a little thicker. The final layer should be the thickest paint mixture. This mixture often isn’t a mixture at all. This paint is usually straight from the tube.

Paint Mixtures and What They Are Used For?

Pallete Knife 1 (2)To make a thin paint mixture, an artist will mix paint from the tube with solvent such as mineral oil. The more solvent that is mixed with the oil paint, the thinner the mixture is. The thinnest mixture can be used to “draw” outlines of subjects in the composition and to lay down shadows and darks in the painting. The thickest mixture can be used for details. It is important for the oil painter to remember to gradually thicken the paint instead of going from a very thin paint mixture to a thick mixture. The gradual change in thickness is important to the process.

Why it is Important to Paint Fat Over Lean?

A new artist may wonder, “What difference does it make to paint one thickness of layers over another?” Well, it can make a lot of difference to the look of the finished painting. Thin paint dries a lot faster than thick paint. If an artist used thick paint on the canvas and then put a layer of thin paint on top of it, the painting would dry improperly. The thin paint would dry on top of the thick paint and the thick paint would still be wet underneath. This would cause the thin paint to crack, ruining the oil painting. In a properly layered painting, the whole painting dries at a similar rate, so no cracking occurs. An artist can’t be great if his paintings don’t last long enough to become famous. Using this process can ensure the long life of an oil painting so that it can be passed down for generations to come.

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