Developing Metallic Surfaces
The airbrush is used extensively in the development of different types of surfaces, both in illustration and in painting. Metallic surfaces have traditionally been created with an airbrush because of its ability to render objects in a photographic manner.
There are two basic metallic surfaces to consider: matte, such as steel, rust, or galvanized; and reflective, such as polished stainless steel, chrome, or gold. Both are easily achievable with the airbrush but utilize two completely different types of techniques.
Matte–This surface is dull and non-reflective and is generally developed with a freehand technique utilizing soft masking (hand-held) and a variety of airbrush sprays. On a matte metallic surface, there is an overall coloration that is minimal; it’s developed by a vignette that moves from light to dark across the surface. Stippled sprays are used to keep the object matte and to give it texture.
A sheet of steel can be developed with a vignette of blue sprayed in a freehand manner from one side of the object to the other. The natural dot pattern of the airbrush lends to the feel of the steel surface. If the surface is coarser, such as with rusted steel, then a heavier dot pattern (stipple) is utilized to replicate the look of the coarse texture.
Stippling can be accomplished in two different ways. Some airbrushes are adaptable to stippling tips or the tips are removed to spray larger dots. The second method is to restrict the air pressure to one or two pounds (psi) with the air regulator; the airbrush does not spray “properly” and produces larger dots.
If masking techniques are utilized for a matte effect, they are normally of the soft masking variety (hand held without adhesive).
Reflective–When you think of “airbrush art,” high-sheen reflective surfaces come to mind, whether they are robots of science fiction illustration or silverware in a sharp-focus realist painting. The unique ability of the airbrush as a tool to depict the realism of a shiny metallic surface is well known. The key to achieving this is to think in terms of painting what is being reflected from within the object, rather than trying to paint only the object’s surface.
Normally, in developing this type of surface, the artist will use a combination of freehand spraying and hard masking (self-adhering frisket or acetate). No matter what the shape or object is, to make it appear shiny, it must reflect its environment.
A simple method to accomplish this–particularly for beginners–is to paint warms (e.g. brown) and cools(e.g. blue) adjacently to give the appearance of the environment that is outside the reflected object being reflected in the object. To the surprise of some, you cannot make an object resemble chrome simply by airbrushing it silver.
As an example, draw a square on a sheet of paper and paint a vignette of blue going from light to dark, top to bottom. Let’s say that the square is outdoors. After the paint dries, cover with a sheet of frisket film and cut a wavy line going across the center. Lift the top half of the film and airbrush along the line with dark blue (which indicates the sky reflection). Let it dry and reapply the frisket film. Lift the bottom piece and spray along the line with light brown for the reflection of the ground. Remove both pieces of film and there will appear to be a reflection in the square, making it look shiny.
TIP: To develop a concave effect, the sky would be reflected in the bottom and the ground in the top. Remember that reflections are always distorted or abstract, and local color (the color of the object) is muted.
Reprinted with permission of ARTtalk.com