First prepare the india ink in the slate slab, then mix it in three or four different intensities .in the china saucers. Wet the paper, using the sponge and clean water, then take up all water which stands on the surface. If the paper is not damp it will be difficult to prevent the color from drying quickly and producing hard lines in the wash.
Find by trial on the border of the paper if the most dilute saucer of ink is of the desired intensity for the first exercise. With the brush full of this ink begin at the top of the space, and, working from side to side, lay on the wash as quickly as possible, keeping the board slightly tilted so that the surplus color will drain toward the bottom of the space. When the lower line is reached, squeeze the color from the brush and take up the surplus color from the paper with the brush tip. Care must be exercised to prevent one part of the wash from drying more quickly than another as this is fatal to a smooth wash. The ability to do this well can come only by practice.
The second wash is laid similarly except that the first brush full at the top of the space is clear water. Then a brush of diluted ink from the next saucer is used and so on, each brush full being darker than the other until the darkest part at the bottom is reached. The even grading of the result will depend upon the skill and care with which the darker color is added.
In the third rectangle the previous process has been reversed, the darkest color used at the top and more water added as the wash progresses downward.
The objects in the lower rectangles are given to illustrate the fact that both lights and shadows vary in intensity. The surface or part of a surface to which the sun's rays are perpendicular, is always the brightest, and the degree of brightness diminishes as the surface is turned away from this position. These contrasts become less pronounced as the distance from the observer to the object increases. This fact may be employed in rendering to give the effect of relative projection of building parts. The walls nearest to the observer are rendered more brilliantly than those at a distance and the detail of the distant parts is kept less distinct than that close up. The student can observe this everywhere in nature. The greater the distance, the more indistinct the detail and color contrasts.
In rendering a curved object such as the cylinder of Plate 18, its lighted surface should first be modeled by a very light graded wash as indicated, showing the parts of greatest light intensity, etc. Then the shaded part and the shadow should be similarly treated. It will be noticed that the shadow is slightly darker than the shaded surface. This is caused by light being reflected back onto the shaded surface from the bright parts of the wall on which the shadow is cast. Because of this reflected light, the brightest part of the shade of a curved surface is usually directly opposite the most intensely illuminated point. The shade line of such a surface is not really a distinct, clean-cut line, but shadow lines are always sharp and well defined. The mouldings illustrate the principle of reflected light in shade and shadow.
The Attic base of Plate 14 will also serve to illustrate the varying intensities of light and shade and the effect of reflected light.