The preparation of a painting ground will differ depending on the medium. If oil paint comes in direct contact with a canvas or board it will cause some deterioration. So it is best to follow a few basic steps.
Traditional Oil Painting Ground (canvas or wood panel): Traditionally, oil gesso was used as the painting ground for oil (and alkyd) paintings. Since the oil in this sort of gesso is detrimental to the surface it is suggested that one use sizing of some sort.
- Rabbitskin glue is most often recommended. Make a solution of approximately 2 ounces of rabbitskin glue to one liter of cold water. Place in pan and heat until glue is dissolved. NEVER BOIL GLUE. Allow the glue to cool to room temperature. If it takes on the appearance of jelly, then you are ready to apply it. Heat again until it dissolves (chalk dust or whiting can be added at this point, but is not necessary). Apply liberally to the surface to be painted. The sizing should penetrate into the fibers and will not create an even surface.
- Once the sizing has cooled, One may begin to brush on gesso. Use broad regular strokes in one direction. Allow to dry completely. The drying will vary, but it will probably take several days. When dry, sand surface lightly to take off fabric burs. Repeat gessoing process, but brush across the directional strokes used in the first layer. Once dry, it will be ready for paint, although one can continue the sand and paint process to create smoother grounds.
Acrylic Gesso: Acrylic gesso can be used as a ground without any sizing or other surface preparation. Oil paint will adhere to surfaces that have been coated with acrylic, but acrylic paint will not adhere to oil surfaces. So acrylic gesso is a good ground for both acrylic and oil media.
- Brush gesso directly onto raw canvas or panel using long regular strokes in one direction. Once dry the surface can be sanded. Then apply another coat of gesso (the first one will soak into the canvas or panel and act as its own sizing) using long regular strokes across the first. Once dry, the surface can be painted or one can repeat sand/gesso process.
Modeling Paste: If a painter wants to create impasto effects (thick surfaces) or have more dimension to the surface of the paint, they can use modeling paste. It is recommended that modeling paste be applied before any oil-based material is put on canvas. It would go on after the sizing when using oil gesso or directly onto the acrylic gesso.