Without considering its shape, which can take a thousand forms – and is not even considered here – the shadow mass is produced graphically in a short time by darkening a sheet of light-coloured paper to the desired degree with charcoal powder and cotton or chalk powder and a rubbing brush (Wischer, estompe) or whatever.
- The effect of this process, whereby the bulging and indenting particles of the paper are equally darkened, is called velvety (velouté, sammtartig).
- On the other hand, if the drawing material (chalk, charcoal or graphite) only touches the surface of the bulging parts of the paper, leaving the deeper parts of the paper (in microscopic terms) intact and therefore light: this effect is called crisp or crunchy (prickling).
Therefore, one of the main qualities of a shadow is its serenity; in a drawing, therefore, the shadow should be corresponding, i.e. velvety. Objects in shadow cannot be definitely distinguished with complete precision; their shape is rather a matter of the imagination, and therefore another of the main qualities of shadow is mystery. This property is imitated and characterised by an indefinite faint spottiness.
There is always a layer of air, more or less illuminated, between the object in shadow and the eyes of the spectator.
This layering is a powerful factor in the artistic perfection of the drawing. This effect can be achieved by treating the shadow with a velvety and then again with a crisp treatment, so that both the colour of the paper and the first velvety treatment remain visible under the crisp one, thus giving the impression of three layers on top of each other.
The shadow should therefore be calm, mysterious and layered, i.e. transparent.