Can the action of your character be interpreted by the reader if every facial expression, garment and textural line is lost? The technique of silhouettes is particularly relevant in book illustration, which may not be expressive when the work is viewed at the actual size. If the action of the character in the illustration is not clear, a silhouette can be useful to determine the direction of the character, what position the limbs are in and what emotions are being communicated in the pose even before the eyes and the details of the costume can be distinguished.
Start by taking a simple character sketch and filling the entire character shape with one dark value. Do not draw in the facial features, garment folds or other internal details, but just the overall shape. Look at the figure at the actual size and at a much reduced size and try to express in a few words what the action is, such as “reaching for the top shelf”, “hiding behind the chair” or “leaning away from the dog”. If the character shape can be interpreted more than one way, then the major shapes in the pose may need to be more distinct.
Often, the confusion of a gesture can be caused by overlapping body parts. If the body parts appear to be connected or fused, then they may be read as one single piece, such as an arm touching the body, or two legs aligned behind each other. In this instance, a slight adjustment in the drawing can clarify the gesture, such as an arm slightly away from the body, the hand held at a different angle, feet slightly apart, or the torso turned slightly. The pose does not have to be modified very drastically. The slight negative space can help indicate which part of the drawing is ending and the next part is beginning.
A silhouette also helps to evaluate whether it expresses the emotional feeling of a particular gesture. A character in the act of being frightened may be pulled in, have their shoulders up, the knees bent and the body weight pushed back. The character may have been curious, leaning forward, but their feet firmly in the ground. If the feeling being portrayed is confidence, then the pose may be more open, chest out and legs in wider stance. While the facial expression should reinforce the pose, it should not be the only thing conveying the emotion. If a character may be drawn with a happy expression on the face, while the body language may convey that the character is frightened or unsure, it can make the illustration confusing for the reader and not express exactly what you want to illustrate, even if the drawing is executed perfectly on paper.
Silhouette is not limited to character. Props and costume can contribute to this process as well. If the character is wearing a large, thick coat, it may appear to have one long line if an arm is bent under the clothing, which could make the arm appear straight. If the character is carrying a backpack, it is important that the outline or strap of the backpack is separate from the main body so that the arm does not appear to be attached to the torso. If you have a larger illustration with more than one character, you can test the readability of one pose against another to make sure that you are not accidentally creating an additional shape in your work that may distract from the main action. The same applies to cropping as well; a drawing can be cropped poorly at the feet or hand so that the main character is obscured or unclear.
A character should not be judged by whether it makes a beautiful silhouette; it should be judged by its clarity and whether the gesture is being communicated with the body, even if it appears exaggerated in drawing and the silhouette itself. Even if it has a wider stance, leaning slightly away from an action or an arm held at a sharper angle, or if it is separated more clearly in the silhouette can aid the storytelling of what the action is and does not require extra explanation. Once this can be read quickly and easily from the silhouette, then line weight, facial expression or other details can be added and refined to further enhance the action.