How to make an underpainting - it makes painting easier
The old masters would paint in a systematic way.
Each layer of the painting had a specific goal.
They painted with an underpainting before finishing with the overpainting. This made the painting process easier. The problems of drawing, tones, and color could be worked out separately. The artist could then concentrate their full attention on one painting problem at a time.
While Underpainting, there was no color to think about. The painter could devote all of their time to working on the tones of the painting. A very logical thing to do...
...to make things easier!
An underpainting really can be classified as any paint that has dried and is again painted upon.
Your underpainting is where you build your foundation. Your main areas of light and dark are planned out in your underpainting. Some people paint an underpainting in one or two colors and some use a full palette.
Personally, I like to make an underpainting in one or two colors. I will establish the main part of my painting and worry about color later, when I can devote my full attention to it.
Think if you had to type a letter, do a math calculation, and cook a meal, all at the same time. It's kind of hard to concentrate on all three things at once isn't it? Painting provides different problems, but they are definitely problems. If your colors are wrong, you won't be happy. If your tones are too dark, you won't be happy. Wouldn't you type that letter better if you were concentrating only on typing that letter?
It is the same with an underpainting. Forget color for now. It's time to think about tones and drawing. You don't need the added burden of color right now.
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.
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 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 more slowly.
Don't Make It Harder For Yourself
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.
Titian is an artist famous for his underpaintings. It is said he painted most of his painting, the underpainting, using three colors. Red, black, and white. All his stronger colors are then applied in the overpainting after he has worked out his drawing problems.
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.
• Tonal values
• Special effects such as getting a glowing or transparent look.
• And others...
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.
If you look at the paintings in museums, you will sometimes see the underpainting showing through the layers of paint on top. Sometimes the painting wasn't finished and the underpainting is very clear.
Look at the illustration to the left. This is a detail of a painting by Rubens.
The arrows point to where you can clearly see his underpainting.
This underpainting was done in brown alone and you can see it very clearly in the photograph.
Here is how I go about painting my underpainting.
I will use only black and white or sometimes a color such as burnt umber and white.
I have no fear of mixing mud because I am using only 1 or 2 colors.
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. Hey isn't that great, I don't have to worry about mixing mud! How can you get mud when you are using one color?
I do not 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.
When a house is built, you cannot put the windows on the house before you have put down a foundation, added walls, etc...The windows are like color in a painting. And the foundation and walls are like an underpainting.