Tips on Underpainting
One of the most important aspects of a painting is value and contrast. Correct lighting and dark enough darks. These important aspects can be worked out without the problem of wondering what color to use and how to make it the correct shade or value. While Underpainting, there is no (or very little) color to think about. Many of these problems could be worked out during this stage. The artist could then concentrate their full attention on one painting problem at a time.
The underpainting is where you build the foundation of your painting. An underpainting really can be classified as any paint that has dried and is again painted upon. Although some people will use a full palette, most underpaintings are done with one or two colors. If you are not skilled in color mixing and getting the correct value without thinking too hard, a monochrome underpainting will help you work out some of the most important problems of your painting.
I like to make an underpainting in one or two colors. Sometimes I use a full palette. I will first establish the main part of my painting and worry about adjusting or brightening the color later, when I can devote my full attention to it.
For a beginning or even intermediate painter, using a full palette to begin a painting can be very confusing. You are having to decide on color, value, form, contrast, placement, composition etc. It could seem very hard to concentrate on all of theses things at once. If you were to begin to try to learn to juggle, you would not start with four items, you might want to start with two or even one, learning to throw one ball in the air and catch it, before trying four. So, for now, forget color and concentrate on tones, values and contrast.
You should want your underpainting to dry quickly because you will paint over it. Therefore you should use mediums that will help your paint dry faster. The less medium in your underpainting the better, but if you add medium to your paint make sure it is quick drying.
In oils, Burnt Umber, Burnt Seinna, Raw Umber, Burnt umber, are very fast drying paints, and will do well for underpainting.
Using a medium that has a lot of oil in it is a bad idea. Adding oil to your paint will make your paint dry slower. Of course this is not what you want from an underpainting. As you add layers to your painting, they should contain more oil in them. This is technically the right way to paint to prevent damage in your painting.
Perhaps you have heard about the term 'fat over lean'...I will explain this term, to those of you who do not understand it, in a minute. Your painting can crack, bubble, and other problems will result if you paint a very oily layer of paint as your underpainting and then put a non oily layer on top of this. Why?
The layer on top will dry all the way through before the layer underneath has dried all the way through. While this layer underneath is drying it will contract. Literally, the paint layer will move! Your eye cannot see it, but it happens. This moving of the paint will crack the paint layers on top which have already dried and stopped moving. A good analogy is an earthquake. When layers of the earth that are underground move and shift, the surface of the earth shakes and cracks. We see this as an earthquake. This is what happens in your painting while it is drying.
If you have a layer on top has dried, and the underpainting hasn't, an 'earthquake' could result. And then your paint will crack, bubble, and other similar problems occur. This is one reason you should paint 'fat over lean' This simply refers to the amount of oil in your paint. Oil is known as a 'fatty' medium. So fat over lean means that your first paint layers should contain less of a fatty medium (oil ) in them. The layers on top should contain more oil so they will dry slowly.
--Don't worry about details yet -- What an underpainting does is divide your painting problems into stages. An underpainting is not a layer to think about color. It is the time to think about drawing and composition. Light and dark. Big shapes. Establishing the main parts of your painting. Details are not part of an underpainting. Underpainting is a preparation layer. You must keep in mind that you are painting this layer to help you with the paint layers that will follow.
Painting can be thought of as solving a series of problems. Painting is hard enough without you making it harder on yourself by trying to solve every problem all at once.
Think of the problems you have to solve.
Even if you just take color by itself you have a number of problems that need to be solved... Color can be used opaquely and transparently. It can be used thickly or thinly. How are you supposed to concentrate on all of these problems at one time? You don't have to. You can divide the problems up and take care of them separately. Using an underpainting is a great way to do this. In this way we do not think about color until later. We think only about drawing and composition at first. Getting the right tonal values. Many people simply use black and white for their underpainting. Some people do a very rough lay-in. Other people do a more complete job on their underpainting. The painting to the left started as an underpainting, but I got it to a point where I liked it as it was, and just went no further. It was painted with Burnt Umber and paint thinner only, using the bare canvas for the light areas, wiping out as I painted.
Here is how I go about painting my underpainting. I will usually use only burnt umber and white, or sometimes raw seinna, and white. I do not have to think about color yet as I am using only 1 or 2 neutral shades. Also, I can freely lighten or darken my painting simply by adding more white or black (or burnt umber if that's what I'm using.) I do not use much medium at all. I paint very freely without regards to mistakes! I can always wipe out areas and start again since an underpainting is the first layer of paint.
If I am not happy with the result I am getting I will simply use my palette knife and scrape off what I have done or use a rag with some turpentine on it to wipe off the paint and begin again.
I concentrate on my tones; getting my light and darks correct. I am making the painting in monochrome. One color.
I don't paint very thickly at this stage of the painting process. More paint will go over this underpainting and I am aware of this. When this underpainting is dry, I can then begin the process of the overpainting. It is at this point that I will gradually add color. The more I paint over the underpainting, the more color I will add.
I will not have to worry about the main 'structure' of the painting. It was already taken care of in the underpainting. As I get closer to completing the paintng I will add more details and high lights. For an example of an underpainting done with several colors click here. This is a painting in progress. If you are a beginner, I would not suggest you use this many colors for underpainting.