Oil paintings are built up from layers of paint.
Oil painting is a slow process because each layer of paint must be completely dry before the next layer is added. The fundamental guideline of oil painting is always apply fat over lean, which means you should start with a layer of thinned oil paint and add increasingly thicker coats to build texture. Oil paints are traditionally thinned with turpentine and thickened with linseed oil. Linseed oil decreases drying times and increases the paint's flexibility so thick layers do not crack.
Instructions
1. Select the colors for your base layer. Squeeze an inch of oil paint from each tube into a different section on the palette. If you are creating your own colors, mix the paints together on the palette until smooth using a brush or palette knife.
2. Add thinner to each of the paints in the palette sections, a drop at a time. Using the knife or brush, mix until the consistency is thin enough to create an opaque wash when applied to the canvas. Apply a dab of thinned paint to the canvas and see how the texture appears on the canvas. Add thinner to the paints in the palette until you are satisfied with the consistency.
3. Wipe away test spots on the canvas with a cloth and create the first layer of your picture using brushes, palette knives or a combination of the two. Allow the first layer of paint to dry completely. This can take up to two days, depending on thickness, consistency and room temperature.
4. Prepare the oil paints for the second layer in your painting in the same way as before, but do not use as much thinner. The second layer should be a little thicker than the first and slightly textured when you test it on the canvas. Paint the next layer of your picture. Allow the second layer to dry.
5. Add a drop of linseed oil to each color during preparation for the next layer, to increase the paint's texture and flexibility. There is no need to thin the paint for more than one or two layers.
6. Increase the amount of linseed oil in each coat of paint as you build up further layers, allowing each one to dry before applying the next. The thickest and final coat takes the longest amount of time to dry, but if you have prepared the paint correctly at every stage, there should be no cracking or movement on the canvas.
7. Leave a completed painting to cure for at least six months, uncovered and unframed. Oil paint cures by oxidation and requires oxygen from the air to set permanently.
