The technique of hatching gives the line an additional potential for the clarification of plastic relationships and of light phenomena. In hatching, parallel, short, equidistant, more or less straight lines create static and tectonic (structural) values by marking individual body planes. Gently curved hatching stresses the roundness of the body and can also accentuate, as tone value, shaded parts of the representation.
The Three Trees, etching with drypoint and engraving by Rembrandt van Rijn, 1643. 21.3 × 27.9 cm.Los Angeles County Museum of Art, (Los Angeles County Fund, 8.31), www.lacma.org
Cross-hatching, in which two layers of hatching intersect at right angles, reinforces the body-and-shadow effect. Known since the days of Michelangelo and Dürer in the 15th and 16th centuries, this artistic technique is often used with slanted or even curved hachures for the linear rendition of rounded parts. In rigorously monotone drawings, this method is the most suitable for the depiction of spherical bodies. The human body, with its highly articulated surface, can be modelled in this fashion very clearly and precisely. For 17th- and 18th-century engravers, this process became the most important means of drawing. All of these different possibilities of linear rendition can be achieved with pen and crayon as well as with the brush. Plane techniques
Linear techniques of drawing are supplemented by plane methods, which can also be carried out with crayon. For example, evenly applied dotting, which is better done with soft mediums, results in an areal effect in uniform tone. Various values of the chiaroscuro (pictorial representation in terms of light and shade without regard to colour) scale can also be rendered by means of dry or moist rubbing. Pulverized drawing materials that are rubbed into the drawing surface result in evenly toned areas that serve both as a closed foundation for linear drawing and as indication of colour values for individual sections.
More significant for plane phenomena, however, is brushwork, which, to be sure, can adopt all linear drawing methods but the particular strength of which lies in stroke width and tone intensity, a medium that allows for extensive differentiation in colour tone and value. Emphases created by the repeated application of the same tone provide illusionistic indentations that can be conceived of spatially and corporeally. Colour differences result from the use of various mediums. Brushwork also lends itself to spatial and plastic representation, just as it can constitute an autonomous value in nonrepresentational drawings.
All of these effects of monochrome drawing are accentuated with the use of varicoloured mediums of a basic material; for example, coloured chalks, drawing inks, or watercolour. While these mediums enrich the art of drawing, they do not widen its basic range. The drawing surface
To these graphic elements must be added another phenomenon the formal significance of which is restricted to drawing: the effect of the unmarked drawing surface, usually paper. Almost all studies (drawings of details), many autonomous sheets, most portrait drawings, as well as figure compositions, still lifes, and even landscapes stand free on the sheet instead of being closed off with a frame-line. Thus, the empty surface, suggesting by itself a spatial background to the drawing on it, contributes actively to the artistic effect.
Even within line composition, the surface left blank fulfills an essential role. Among the details conveyed by the empty space may be the planes of a face, the smooth width of a garment, the mass of a figure or object, the substance the borders and nuances of which are indicated by the drawing. Even the space around individual objects, the spatial distance between them and their environment, the width of a river and the depth of a landscape may be merely signalled by the drawing and filled by the void.
This void can itself become the dominant form enclosed by lines or contours—for example, in decorative sketches and in many ornamental drawings that make use of the negative form, an effect attainable also by tinting the blank planes. Relationship between drawing and other art forms
The bond between drawing and other art forms is of course very close, because the preliminary sketch was for a long time the chief purpose of the drawing. A state of mutual dependence exists in particular between painting and drawing, above all, in the case of sketches and studies for the composition of a picture. The relationship is closest with preliminary sketches of the same size as the original, the so-called cartoons whose contours were pressed through or perforated for dyeing with charcoal dust. Once transferred to the painting surface, the sketch had served its purpose.
On autonomous sheets, too, the close connection between drawing and painting is evidenced by the stylistic features that are common to both. Drawing and painting agree in many details of content and form. Measurements; proportions of figures; relationship of figure to surrounding space; the distribution of the theme within the composition according to static order, symmetry, and equilibrium of the masses or according to dynamic contrasts, eccentric vanishing points, and overaccentuation of individual elements; rhythmic order in separate pictorial units in contrast to continuous flow of lines—all of these formal criteria apply to both art forms. The uniform stylistic character shared by drawing and painting is often less severely expressed in the former because of the spontaneous flow of the unfettered artist’s stroke, or “handwriting,” and of the struggle for form as recorded in the pentimenti (indications in the drawing that the artist had changed his mind and drawn over his original formulation). Furthermore drawing can stimulate certain aspects of movement more easily than painting can through the rhythmic repetition of a contour or the blended rubbing of a sharp borderline.
Still closer, perhaps, is the bond between drawing and engraving, which works with the same artistic means, with monochrome linearity as its main formal element and with various tone and plane methods closely related to those of drawing.
Drawing is more independent than sculpture because sculpture uses a three-dimensional model. As a result, sculptors’ drawings can always claim a greater degree of autonomy. (For the special position of the architectural sketch, see below Subject matter of drawing.) Surfaces
One can draw on practically anything that has a plane surface (it does not have to be level)—for example, papyrus and parchment, cloth, wood, metals, ceramics, stone, and even walls, glass, and sand. (With some of these, to be sure, another dimension is introduced through indentations that give the visual effect of lines.) Ever since the 15th century, however, paper has been by far the most popular ground.