The next time you comb the beach or walk through a natural trail and find a flat-faced, smooth stone, pick it up to use as an unexpected canvas. You can use a larger, hand-painted stone as a doorstop, or you could gather many stones to use as vase fillers or landscape decorations. You can also use your natural stone painting project as an activity for children. Participating children will appreciate your adventurous use of materials and will also take away a personalised keepsake.
Scrub your stones clean with your scrub brush and hot water. Allow your stones to dry completely before proceeding.
Paint the stones with a layer of overall colour if you want to cover the entire stone with paint. Use your large, flat tip brush. Paint one flat side of each stone first, allow the paint to dry, and then paint the opposite side. If your first coat of paint dried semi-transparent, and you wanted a more opaque background, add a second coat of paint.
Trace a light outline of any designs you plan to paint on your stones. Skip this step if you just want to paint a large amount of stones to use in a decorative display.
Paint any dark outlines over the lines you drew on your rocks first, and allow them to dry. Paint the rest of the rocks following the sketches you drew. Since controlling and blending multiple colours is difficult on the rocks' smooth, hard surfaces, you'll want to paint each colour separately and allow each colour to dry between applications. For broad shapes, use your medium brush; add details to your work with your narrow tip brush.
Coat your work with varnish once the stones are totally dry.
If varnish isn't readily available, substitute clear nail polish.