Things You'll Need
Acrylic paint dries quickly and you can modify it with acrylic gels or water to create paintings that resemble those done with oils or watercolors. Acrylics come in several finish types, including gloss, matte and satin. These different finishes and modifying properties allow artists to create variations in shading and finish that make it possible to render 3D effects quite easily, bringing depth to their works of art.
Sketch your painting lightly first. Some artists prefer to paint directly to the canvas, without a light pencil sketch for a guide. Determine your light source and draw the three-dimensional elements accordingly. For instance, if you depict a building and the light is coming from your left, draw the shadow on the building's right side. The shadow will be your 3D effect. Add this effect by extending the side of the image back toward an imaginary horizon line on your canvas and separating it with a light line that shows the portion you will alter for 3D.
Paint your image, paying attention to the front surfaces, which you will not alter for dimension, first. You can add awash, a thin layer of paint, to the areas you'll paint in 3D, but it isn't necessary. When you've completed all the paint application to the front surface of your image, begin building the shadow layers in the portions of the image that extend away from your front surface and toward the horizon line.
Paint in layers in the shadow areas of your painting. Apply the layers in such a way that the brush follows your shadow lines toward the horizon. Apply one or two more coats to the 3D areas than you use on the surface of the image. The contrast and where you place it is what gives the painting its 3D effect.
Some artists who work in acrylics like to apply a powdered acrylic onto the wet paint and let it dry to give a 3D effect. This not only helps increase the look of dimension, but adds a 3D texture as well. You can also apply several layers of acrylic gel to build up the areas you want to appear in 3D.