Creating oil paintings with rich and intense glazes of transparent paint doesn't have to be a complicated task. In fact, by working from a monochromatic under-painting, or grisaille, your oil paint is less likely to become grey or muddy. Establish-ing composition and value early in your painting process allows the remainder of your efforts to be devoted to layering brilliant color and creating form with shadow and light.
"Creating oil paintings with rich and intense glazes of transparent paint doesn't have to be a complicated task"
Step One: Establishing Values
Before beginning my painting I choose the color of my under-painting. This color varies depending on the subject matter I am working with. Keep in mind that your under-painting will be visible through the subsequent layers of paint. Daniel Smith Original Oil in Sepia is used for the study of pears. This wonderful color has a wide range of value from a deep brownish-black at full strength to a slightly warm transparent glow when mixed with painting medium. I thin the Sepia paint with Daniel Smith Odorless Mineral Spirits and Daniel Smith Painting Medium for Oils and Alkyds to create a tone in the middle of this range. This mid-tone is then applied to my painting surface a Gessobord by Ampersand with a hog bristle brush. I look for the darkest values in my still life and add Sepia paint to those areas. For the lighter areas of the painting I use a rag to rub away the initial layer of paint.
Step Two: Refining the Under-Painting
At this stage of the painting I begin to blend and add form to my value study. Using hog bristle brushes I add paint and work it into the surface of darker areas. To remove paint in lighter areas of the study I often clean my brush with mineral spirits and use the slightly damp, clean brush to pick up extra paint (a lint-free rag also works well for this process). Be sure to take your time and observe all of the subtle variations in your study as this painting is the foundation for your glazes. A softer brush, such as an oil blender or black sable filbert, may be used to soften the brushstrokes. In addition, remember to mix painting medium with your oil paint as you work and add only a thin layer of paint in this step this will ensure that your under-painting will be dry and ready to be glazed with color in about 24 to 48 hours.
Step Three: Adding Color
Although it can be difficult to stop working and let a painting dry, in order to achieve bright, clean glazes it is necessary to work over a dry under-painting. A glaze is simply a transparent color, often thinned with painting medium or linseed oil, applied over the top of your under-painting. I am working with three of my favorite transparent colors Quinacridone Gold, Sap Green and Quinacridone Burnt Scarlet. If you are unsure if the colors on your palette are transparent try this test: draw a black line in permanent marker on a scrap of canvas or board, mix your paint with a small amount of painting medium and brush it over the line if you can clearly see your black line you have a transparent pigment. If your line is completely obscured your color is opaque. Opaque paints are wonderful for covering-up areas but stick with transparent or semi-transparent colors for your glazes so the hard work on your under-painting shows through. Mix your transparent colors with painting medium to give a fluid, easy-to-brush viscosity. Apply glaze layers with a soft brush such as a synthetic mongoose or black sable to avoid brushstrokes, and add multiple layers to create rich color.
Step Four: Finishing Touches
By now, transparent glazes have added color and life to the monochromatic under-painting. To capture some of the volume of my subjects I like to use small amounts of opaque and semi-transparent colors for highlights and form. Adding small amounts of semi-transparent Minnesota Pipestone into the wet paint gives the pears a more realistic look. I also add small amounts of white to bring out the shape of the pears and add highlights. A soft oil blender brush removes all of the brush marks from the surface in this final stage. After six to nine months your painting can be varnished which will add further depth to your layers and protect the surface of your work.