What people often call latex paint is in fact an acrylic. Acrylic-based gesso is a common ground or primer for fine art paintings done in oil. Therefore, there is no need for a special preparation prior to painting with artist oil paints over latex. The main concern is to isolate the surface of whatever you are painting to protect it from the oil in the paint. If you use acrylic gesso, you will have more archival results, meaning greater durability over years. Latex house paint is a ground sometimes used by student artists to save money. It is not as archival as a professional grade gesso, but will work fine for home projects.
Instructions
1. Stir the latex paint or gesso. Don't over-agitate gesso; stir it gently.
2. Paint one coat of latex or gesso on your surface. Apply with vertical strokes. Allow to dry for approximately 30 minutes.
3. Apply a second coat. Alternating directions promotes better sealing, so use horizontal strokes this time. Allow the second coat to dry.
4. Apply a third coat. Use vertical strokes. Allow to dry. Once this coat dries, you may paint in artist oil paint on the surface.
5. Lay out the oil colors on the palette. Use the palette knife to mix them. Add medium to increase flow and fluidity. Be careful how much you add. Too much fluidity on a vertical surface like a wall can make the paint drip. Clean up any mess with mineral spirits.
