Oil on Claybord
Most oil painters choose Gessobord over Claybord for their work in oil because they prefer a less absorbent panel. Gessobord needs no preparation and may be used right out of the wrapper. However, some oil painters prefer Claybord because they work in many layers with glazing techniques. The absorbency of the clay ground enhances their technique and adds a unique style to their images.
Oil painting on prepared panels is an art that dates back centuries. Traditionally, panels were prepared with a mixture of chalk and hide glue. Modern 'gesso' contains acrylic polymer binders that render the surface less absorbent than Claybord. Claybord's absorbent coating will result in oil paints, applied to the untreated surface, to dry very rapidly and to a matte finish. This characteristic is ideal when working with an indirect process of underpainting and glazes.
Louise LeBourgeois, The Far Away #539, 30x60, oil on Ampersand Claybord
If you prefer the quick drying time of the Claybord panel, no additional preparation is necessary. However, if you want to lessen the absorbency of the surface, try one of the techniques below. Once prepared using these techniques, subsequent layers of paint will dry more slowly and maintain their luster.
Completed paintings should be sealed with a varnish for protection and to bring out the luster in your paints. The paint must be thoroughly dry before varnishing. This drying time will vary greatly from one painting to another. Our panels do not lessen the six-month rule of thumb required before varnishing. Although your oil paint could be dry to the touch in a few days, it will still need more drying time before it is ready to varnish.
"Oiling Out" procedure:
One option is to seal the entire board by using an "oiling out" process on the surface before beginning your painting. First, apply a liberal coating of 1:1 drying oil (such as linseed oil) and solvent (such as OMS) to the Claybord surface. You could instead use a fluid, commercially available painting medium if you prefer. Next, allow the mixture or medium to be absorbed into the surface for approximately two to five minutes. Finally, wipe off the excess mixture with a soft, lint-free cloth. This "oiling out" procedure can also be applied to a finished painting after it is completely dry or just to an area that may need to be enlivened.
Toning the Surface
Another option is to tone the surface with a single color to create a background tone that suits your intentions for your painting. Working on a neutral-toned surface helps to create more contrast in the values (the light and dark areas) of your painting as well. Select or mix a color of your choosing and thinly brush or wipe this color over the entire Claybord surface and allow it to dry. This can be done with a little bit of solvent added to the paint or just the undiluted paint on its own. A similar approach is to use this underpainting process to begin to map out the forms in your painting. You can apply the paint to define the light and dark areas as a first step, so when dry, these areas are already defined. This process can also be used for beginning a method of indirect painting, which is another option for using Claybord with oil paints.
Indirect Painting Method
Indirect painting is a process that was used by the old masters, where the painting is created through several glazes of transparent and semi-transparent color. The final image allows light to pass through the paint layers for a visual mix of color and a "lit from within" quality. Since Claybord’s surface is like the old-masters’ gesso, it makes sense that the old-masters’ techniques would work on this panel. By the time that there are three or four glaze layers applied to Claybord, its absorbency no longer shortens the drying time or effects the sheen of the paint. This is also the process that Louise LeBourgeois uses, working in layers to create depth within her paintings, taking advantage of the ultra-smooth Claybord surface.
Underpainting to Reduce Absorbency
Apply an underpainting of a neutral oil color or a commercially available oil medium. Keep the "fat over lean" principles in mind.
Increase the "Fat" Content of Initial Paint Layers
Try adding more medium to your paint to allow better flow and paint consistency when using Claybord. Again, remember the "fat over lean" principles and be aware of the amount of medium in the mixture. Commercial oil paint mediums can be thought of as 50% fat content.
Apply a Non-Absorbent Ground
Apply a thin layer of oil or alkyd ground to the Claybord surface. Use a trowel or putty knife to apply the ground thinly and even out the application with a foam roller with a short "nap" for a smooth, consistent surface. Allow this application to completely dry before beginning painting.
NOTE: Although you can completely remove the pigments from a Claybord panel with mineral spirits or sandpaper, the oils and resins in your paint may stain the board. Also, a mixed-media approach can be used when using Claybord. Try beginning with a thin acrylic wash as an underpainting, scratch into the surface to create detail, and then glaze over detail areas with thin washes of oils. For best results, allow your composition to dry overnight before applying oil washes on top of a fresh underpainting and detail areas to ensure that they are completely dry. Anytime you scratch or sand oil paint, exercise proper safety precautions.