As a growing variety of paint mediums have become more widely available in recent decades, the prevalence of artists working in mixed media has continued to expand. According to Sean Dye, author of "The Mixed Media Sourcebook," mixed media techniques have been in use for centuries (see References at the end of this article). For its sheer diversity, mixed media painting is an art form that holds many interesting possibilities.
Gesso is a canvas primer that encourages the adherence of paint to the surface, and is usually applied in three layers before painting. Since gesso, which means "chalk" in Italian, dries hard, it is usually sanded to a smooth finish with fine grain sandpaper before painting. It can also be used to create texture. Other texture-building mediums, like heavy structure gel and gloss heavy gel, are mixed with paint to build the paint body, or increase its mass and firmness. Of course, watercolors, oil and acrylic paints, gouache, oil pastels, ink and even craft acrylics (which often include metallic colors) can be layered in a single painting to create various effects.
Transfers involve transferring an image from one surface to another, and can be a useful method in creating collages or interesting backgrounds. Some methods are acrylic, xylene, caulking, and heat transfers (see the article on transfer techniques in References below). Encaustic is a method that involves painting with wax, and like with transfers, can involve multiple layers. American artist Jasper Johns painted layers of encaustics over newspaper clippings, which can be seen through parts of his "Flag." Refer to "The Painter's Handbook" by Mark David Gottsegen for tips on creating and painting with encaustics (see References).
Mixed media painting techniques are as diverse as the media being used in a given piece of art. Some basic painting techniques involving layering of transparent colors (known as glazing) and applying different types of brushwork add interest, depth and variety to a mixed media painting. One interesting technique is known as wax resist, and involves simply rubbing a white wax crayon on a surface before painting. The wax-coated areas resist paint or any other medium, such as ink, that is applied to the painting. Use this technique to create highlights in certain areas of the image.
Use a serrated knife to add texture to wet paint, as for corrugated metal effects. Build up surface textures using gesso, heavy body mediums (available in craft and hobby stores), and modeling paste. Allow any mediums not mixed with paint to dry completely before adding other media to the surface. Use sponges to create various textures in paint, such as blurred colors for backgrounds or in organic forms.
Grattage refers to scraping texture in dried gesso, often with a palette or serrated knife. Frottage refers to the technique of rubbing a pencil, charcoal or other drawing medium over an object or textured surface to create an impression of that surface. Frottage can be a useful way to start a piece by informing the lines and shapes.
There are many methods and approaches to mixed media painting. Look in galleries and art and design magazines for new ideas, and start with the resources listed at the end of this article for more information on putting the different techniques to use. And most importantly, do not be afraid to try something new, make mistakes, and enjoy every minute of it.