How to Paint Realistic Looking Rocks

Create several different washes of acrylic paint. Use separate containers and dilute the acrylic paint with water. For umber, concrete, yellow or white colored acrylic paints, use one part paint diluted with 16 parts water. For black or slate gray, use one part paint diluted by 32 parts water. Diluting the paints makes them very forgiving when painting rocks. You can make mistakes and just go over them.

Use a paint brush to apply the wash to several different areas of the rock. Woodland Scenics calls this technique the "leopard spot". Apply various colors of washes to randomly spots on the rocks. Beginning with one of the secondary colors, paint random spots on the rock to cover about one-third of the surface.

Rinse off the paint brush and use a different color to repeat the process, washing different areas of the rock. It is okay if the colors run together as they should blend anyways. Repeat this process with each of the colors you are using until the surface of the rock is covered.

Build the color on the rock until you reach the desired look. Allow the washes to run together and blend to achieve a natural, realistic look. Choose one dominant color to paint the entire rock and set the main tone.

Create the final touches on the rock. Allow the rock to dry to then apply a more concentrated black wash to emphasize cracks and crevices. If going for a sun-bleached effect, use a dry brush to very sparingly add undiluted white acrylic paint and add highlights.