Gesso is chalky and looks like caulk or white paint.
Gesso is a primer that is used to prepare surfaces for paint. Applying it to canvas, paper, wood or plastic before painting prevents paint from sinking into the surface and it adds strength, stiffness and durability to the surface. Gesso is widely available at art supply stores in chalky white, but can also be found in black.
Instructions
1. Spread newspapers or plastic sheeting on surrounding surfaces to protect them from accidental drips or splatters. Be sure the surface you plan to paint is clean and dry.
2. Stir or shake gesso, ensuring it is well mixed and has a spreadable consistency. Dip your brush into gesso and apply to your surface using long, even and smooth strokes. Allow this coat to dry. At this point, it might be ready for paint, but some surfaces are more absorbent than others and may require a second coat.
3. Turn your piece and apply a second coat using brush strokes that are perpendicular to the first coat. If painting on Masonite or another very smooth surface, you might want to lightly sand the first coat of gesso before applying the next in order to get rid of small grainy bits.