How to Draw for Oil Paintings
A complex drawing is quickly lost when the oil colors go on, so simple shapes and contour lines make the best drawings for oil paintings.
The drawing may be made directly on the canvas or it can be prepared before and transferred to the canvas.
When drawing directly on the canvas, PAINT that has been thinned with thinner is the best. Because it is paint, it doesn't need to be isolated from subsequent colors.
CHARCOAL can be used for drawing on the canvas. The charcoal drawing must be isolated from the paint layers with FIXATIVE. Vine charcoal is easier to seal with fixative than compressed charcoal.
The drawing can be made with a PENCIL on the canvas. This must be sealed with FIXATIVE before the colors go on. A pencil's point (if pushed too hard) can make small cracks in the gesso so a thin transparent layer of gesso may need to be applied to re-seal the canvas. If gesso is used in this way the fixative is not necessary
DRAWING FOR OIL PAINTING
A drawing that is going to be TRANSFERRED to a canvas is best done on thin tracing paper because the transfer will be clearer. Tape the drawing to the canvas. Transfer the drawing using carbon paper. Draw over your drawing with the carbon paper beneath it. Use a contrasting color ballpoint pen so you can see where you've already drawn and to get a consistent line size. The carbon transfer should also be separated from the paint layer with fixative or a thin transparent layer of gesso.
HOW DO YOU MATCH COLOR
The wheel is arranged with yellow, the lightest value color at the top and violet, the darkest value color at the bottom. From the top down on the right are yellow-orange, orange, red-orange, red, and red-violet. These are called the warm colors. From the top down on the left are yellow-green, green, blue-green, blue and blue-violet. These are called the cool colors.
Any TWO colors directly across the color wheel from each other are called COMPLEMENTARY COLORS. Red and green are opposite each other on the color wheel and therefore are complementary to each other. Yellow and violet are each other's complements. Yellow-green and red-violet are complements. Complimentary colors when placed next to each other on the canvas intensify each other. Complementary colors when mixed together on the palette neutralize each other. In this chart the pure intense colors are on the outside opposite their complements. As we move to the middle, the complements are mixed together until they become gray, the least intense of all.
All colors come in all values. The pure spectrum colors are in the position of their relative values on this seven-value scale
All paint is a mixture of a dry pigment and a liquid. For oil paint the dry pigment is mixed with linseed oil. Linseed oil is a drying oil that dries by oxidation. That is, it takes oxygen from the air and creates a crystalline solid that encases the pigment in a permanent form. When it's dry it can't be removed.
Oil paint is thick. It comes in tubes. The paints are squeezed out onto a palette where they are mixed together with a palette knife to make the various colors. It's then applied to a vertical canvas with stiff brushes.
Oil paints are slow drying. Usually taking three days before you can put on another coat. The drying time is an advantage and disadvantage. The great advantage is that you have time to refine and adjust what you paint before it dries. This is particularly useful when making gradual transitions from one color to another. Also if you paint something you don't like, it can be removed while wet using a rag, palette knife or rubber squeegee and replaced.
The disadvantages are that when putting two wet colors next to each other they can cross-contaminate if not applied accurately. The palette, the brushes and the wet painting must be handled carefully to keep wet paint off, fingers, food, fabric and furniture.
The paint may be manipulated for up to 12 hours after which you must wait three days for it to dry before going back to make any changes. When oil paint is dry, new colors can be applied over old. Many layers of paint may be applied. If the paint is to be used thickly each layer should be as thick or thicker than the previous layer to avoid cracking.
After a painting is thoroughly dry (three to six months), varnish is applied to protect the painting.