Working with Charcoal
Charcoal has a long and distinguished legacy as a drawing medium used extensively by professional and student artists alike. Since it is so versatile and offers a diversity of line and tone, it remains a basic and indispensable tool for drawing and sketching.
Charcoal is composed of graphite, a crystallized form of carbon. Traditionally, burnt grapevine sticks were used as a form of natural charcoal called vine charcoal. This type of charcoal is made by slowly baking segmented grapevines or willow dowels (or other types of wood) until they are reduced to almost pure carbon.
Vine charcoal is a fine-quality charcoal because it has the ability to produce lines and tones of infinite subtlety as well as robust painterly effects. It is also valuable for the ease with which marks can be corrected by being dusted, or even blown, from the surface.
Other types of charcoal are made by wetting graphite, blending it with ground clay, and then baking it into dried sticks, where the more clay added, the softer the stick. With this process, a useful variety of hardnesses and textures can be produced.
Compressed charcoal is made by combining powder-ground charcoal and a binding agent in a process that results in shorter, break-resistant sticks. These are also available in pencil form, and both types of manufactured charcoal are available in various shapes, sizes, and hardnesses.
The pencil form of compressed charcoal has an outer wrapping of wood or rolled paper for cleaner handling. These can be sharpened to a very fine point, which makes them well suited for meticulous detail. This type of charcoal produces very dense blacks that are convenient to handle but not easily erased.
With charcoal, preliminary outlines can be laid down and then either removed or later painted over. Precise marks can be produced by using the tip of a stick, while larger tonal areas come from using a broad side stroke. Additional tonal effects can be created by crosshatching or smudging with a stump, a kneaded eraser (putty rubber), or a brush dipped in clean water. A kneaded eraser is also effective for lifting out highlights.
Much like pencils, charcoal is also produced in a range of grades, and the different hardnesses can be utilized for creating a variety of tones. Willow charcoal (among the most popular) can be obtained in three or four grades: extra soft, soft, medium, and hard. Each type is available in two lengths: 75mm (3 in.) and 150mm (6 in.). They are also produced in a variety of diameters (of either round or rectangular sticks) with the thickest being about 12mm (1/2 in.). Vine charcoal is most commonly sold in 150mm lengths only.
Charcoal will produce a mark on most drawing surfaces, but best results come from using a paper with a heavy tooth. Here, the crumbling consistency can be best exploited by picking up the grain of the surface and producing a textured quality to a drawing. The paper must also be able to withstand rubbing, blending, and erasing without loosing its "bite." Since there are so many different types of paper with different types of tooth, choose the kind that will best represent the effect that you want to achieve.
Direct application of charcoal on paper will produce very soft, black lines. When applied lightly, it will pick up the surface texture of almost any paper. Large shaded areas can be covered by gently rubbing the charcoal and then further blending by using a cottonwood (absorbent cotton) pad, a kneadable eraser, or your finger. To produce lighter highlight areas, try using a kneadable eraser to lift out the grains of color or add lighter values with white chalk.
A tortillon can also be used to blend the charcoal particles. A tortillon is shaped like a pencil but is constructed of compressed, absorbent fibers. To blend with this tool, lay down an area of charcoal and then work it precisely with a tortillon, using a motion much like a pencil. Or (in a separate area) shave off some charcoal dust and use the tortillon to pick up the minute particles, and then spread them around in either broad strokes or detailed spots or line. A paper stump, which has points on both ends, can also be used for smoothing and blending large areas of charcoal.
The fragility of charcoal does have disadvantages, however. Mistakes can be easily removed but so can intentional marks, so it is essential to fix a drawing immediately upon completion by using a thin coat of a spray varnish called a fixative.
Spray fixatives are used to protect drawings against smudging and abrasion. The aerosol deposits a fine transparent film of lacquer on the drawing surface to hold any loose particles of charcoal in place. Some fixatives can also be used to protect dry transfer products against scratches. When using these aerosols, always hold the drawing upright and spray lightly and evenly. Coating too heavily will spot or stain the work and can also over-darken the tonal quality. Do not inhale the mist and always work in a well-ventilated room.
Drawings from subtle tonal line and shades to those of great starkness and contrast can be created by using charcoal on paper of various surface grains and color. For those who sketch before they paint, charcoal is invaluable for roughing out the initial image on canvas. Whatever the individual need or choice, charcoal remains an indispensable drawing tool that still faithfully serves many artistic applications.