History

• Spatula techniques coincide largely with the advent of oil paint. Tempera and other water or egg-based media demanded other kinds of application, and did not lend themselves to the use of a spatula or palette knife. With the advent of Impressionism in the mid-19th century in France, the surface of the painting became thicker. The use of the spatula gave the paintings a feeling of spontaneity and verve that coincided with the "impression" of the movement of light that these paintings so often capture.
  
  

Impasto

• Impasto is the heavy build up of paint directly on the canvas. The technique of creating the impasto is called scumbling. When you mix your colors on the palette, you can scoop them off with the edge of the spatula or palette knife and apply them directly onto the canvas or panel.
  
  

Applications

• Spatula techniques vary from painter to painter and depend as well on the desired effect. For a smooth and glassy finish, you might load the spatula with a single color and use a broad, sweeping movement across the surface. For more interesting textures, such as a tree trunk, you would lay a mix of color over a pre-painted area, leaving globules of paint and working in the direction of the trunk. Other techniques--such as cutting, swiping or digging into previously applied impasto--can create the illusion of depth or bring a flat object to life.
  
  

Function

• By building up the paint you can create a more dynamic texture and give the painting an attractive physicality. There are technical and theoretical reasons why you may want this effect. From a technical standpoint, recreating the texture of an object you are rendering can bring more realism to the painting. If you are interested in theoretical ideas about painting, creative spatula techniques can emphasize the physical, as opposed to the figurative side of the painting, much in the way the abstract Expressionists did.
  
  

Warning

• One of the problems of spatula use in a painting is that the painting is more likely to deteriorate over time than one executed with thinner paint. Heavier build-ups of paint dry more slowly, as the internal paint and the outside skin dry at different rates. In addition, different colors dry at different rates. These variations can cause cracks in the surface of the paint and adversely affect the adhesion of the layers of paint. That will cause peeling or other problems down the road. Make sure you adhere to the basic painting principle of thick over thin, and if working in oil, use fat (paint with more oil) over lean.