Rays of light can add a unique special effect to a painting. They can draw the viewer in and make a painting come to life. Painting rays of light is an ideal technique to use in paintings of clouds, a forest or an underwater scene. There are certain methods and techniques that have to be followed to get it just right.
Complete the painting without the rays of light. Painting the rays will be the last step. Let the paint become relatively dry, but not completely dry. This will help you to achieve just the right amount of translucency in your image.
Dilute the paint for the rays by mixing a fair amount of turpentine with white paint until you get an almost translucent colour.
Lightly add the diluted paint to your canvas, filling in the areas where the light should shine through. If some areas look too opaque, add less diluted paint to achieve a brighter look. You may also consider adding a small touch of yellow for a sunshine effect or blue for an underwater effect. Continue adding the paint until you are happy with the overall look.
Practice this technique before adding it to your actual painting. Lay out some shades of brown and green or blue on a canvas and use the ray painting technique over those. Once you feel confident, add it to your finished painting.