The art of stippling is building colors in a subtle way using a sponge or a stiff bristle brush. Nearly any type of firm brush can be used for this type of painting. The technique allows the painter to achieve beautiful gradations of color with variations in the intensity of the colors applied. Foliage or backgrounds are great for surfaces using this technique. Use dark, medium and light colors when stippling to create depth.
Using the right tools for the job is important. Soft brushes don't work, but a stiff brush or even an old one with splayed bristles will do nicely. Sea sponges also work very well to achieve gaps and spaces that will allow you to return to those open areas once the foundation color has dried. You can then apply more color or different values of color. Paint trays or plates allow space for blending paint. You'll need a water bin to clean the brush or sponge often in order to keep the colors from becoming tainted by one another. Colors should be well separated on the tray so you can pick up just what you need as you work. You can stipple oil paint over an acrylic base coat, but acrylic paint won't adhere properly and stay fast to an oil painted surface. Paper towels or old rags come in handy for cleanup.
Base coat the project surface with the color of your choice. Let it dry completely before you begin the stippling process. Any time you start stippling prior to complete drying of the base coat color, the brush or sponge will lift the base color from the surface and you'll need to start the project over from the beginning. Save yourself some time and effort by working in stages without trying to rush the job.
Sponge Stippling Techniques
To stipple with a sea sponge, moisten the sponge with water and dry it well with a towel before adding paint to it. The sponge should only be damp to the touch. Small silk sea sponges allow for fine stippling while larger sea sponges offer a looser open effect. Dip the sponge into the color of your choice and tap it lightly on the tray to soften and blend it into the sponge. Lightly tap the sponge onto the surface moving in an "X" or "J" type of shape, overlapping the color as you proceed. Let the paint dry and repeat the step with the next color. If you are using three values, you should work from dark to light, meaning the darkest color goes on first, the second color is then applied and the lightest value will be the final color stippled in place. If you don't work this way, the darkest value will overpower all the other colors. If you wish to use two colors at once, dip one half of the side of the sponge in one color and the other half in the next color. Again, tap the sponge on the tray to soften and blend the paint into the sponge. When you begin stippling, twist your wrist from side to side like a windshield wiper to overlap the colors without too much contamination to the color on the sponge. To do this, apply the sponge to the surface, lift it off and turn your wrist. This way, the paint won't smudge and you will achieve a color variation.
Brush Stippling Techniques
Without moistening the brush with water, load the brush with the color paint you plan to use as the basic stippling color. Swish the brush back and forth on the tray to even the paint out so there won't be globs of color when you apply it to the project. To stipple your project, hold the brush upright and tap the tips of the bristles onto the surface so tiny dots of color will adhere to it. If you wish to gradate the color, stipple longer in place as you move across or down your surface. Using an old stiff brush will result in a slightly more ragged texture. When the color is dry, clean the brush and dry it well. Pick up the next color and repeat the process until you have the look you want.