To paint using this technique you need a primed canvas. Purchase canvas primed or prime your own. The most common priming material is gesso. Gesso will give your canvas surface texture to work on and make your colors look brighter. Gesso is bright white and thick, so you need to adjust the thickness with water. Gesso dries quickly, so work without pausing and apply your primer with a synthetic brush. Apply two coats of gesso to your canvas to achieve a good surface for your oil glazes. The primed layers need to be completely dry before you proceed. Next, apply a medium earth tone thin oil wash to the canvas. Use a glaze of white for the subject and darker values for the background. This step creates a monochromatic image of the subject. Let all your paint layers dry between steps.
Your primed canvas is now ready for the under painting. Do the under painting with opaque color leaving the edges soft to allow for adjustments later. Establish the under painting, then leave the canvas to dry completely. This technique will emphasize the drawing and the painting. Apply the under painting quickly and loosely, the tonal makeup of the painting will emerge and act as a guide for your completed piece. Your under painting will allow your subject to be developed directly on the canvas.
You are ready to start your glazing. Semitransparent light opaque tones applied over darker areas create the illusion of softness. Use this technique to paint soft flesh tones and atmospheric changes. Glazing of dark transparent tones over light areas will create the optical illusion of warmth to the darker tones in your painting. Oil glazes are created when you mix oil color with any chosen medium. Linseed oil is the most popular way to create an oil glaze. The result is a glossy transparent finish. Your glazes need to be dry between layers. Layering your work will allow you to push the limits of your colors and even change the painting at any stage.