Now to get down to a few practical facts of value to the beginner. First of all, decide whether the glass is to be shown light or dark. This depends largely on the surrounding material. If the walls are of light plaster, and strong contrast seems desirable, keep the glass dark; if, instead, the walls are of dark material, light windows will attract more attention. There are many cases, however, where it seems wise to keep certain windows inconspicuous, as a matter of presentation, and under such conditions strong contrast is of course to be avoided. The best way to determine which windows should be dark and which light is by making a preliminary study on tracing paper before starting the final rendering. As a rule those windows nearest the spectator or, in some instances, nearest the center of interest, should show, not only the sharpest contrasts but also the greatest amount of detail. This gives us an opportunity to get a certain variety of treatment in the different windows, which is essential, but at the same time care must be taken not to provoke unrest by overemphasizing the differences of representation. Once a general scheme for the values has been determined upon, it is necessary to reach a decision as to how much detail is to be shown through the glass. This will depend largely on the location of the windows and on the nature of the building. If a dignified facade is to be rendered, it is seldom wise to show much inside the glazing, as curtains and the like sometimes detract from the architectural character of a formal building unless rendered in a very conventional manner. An informal building, such as a suburban residence, permits greater freedom of expression, however, so in a building of this sort it is usually best to show the shades and curtains quite distinctly. Stiffness of effect is avoided if an occasional window is shown open, or with the shutters partly closed, while awnings and screens and such things sometimes add to the feeling of reality. In a formal building if shades are shown in the windows they are usually all lowered to the same point, generally about one-third to one-half way down from the top, or are arranged in some uniform manner, but greater variety of spacing is permissible in less formal structures. Inside draperies harmonize better with the structural lines of the building if shown hanging vertically or nearly so, and for this reason it is often well not to drape them in curves, as curved lines frequently attract too much attention. Neither is it necessary or desirable to show much detail or design in the hangings, though there is no harm in suggesting some simple pattern, as in "4," Figure 36, especially if a sash is unbroken by muntins or other objects. When it comes to the rendering of the sashes and the window frame, treat the woodwork very broadly, merely suggesting by one or two lines all the various members of which the whole is composed. The sash bars will usually be sufficiently well indicated if a single line, representing their shady side, and their shadow on the glass is used. Sashes are, as a rule, left white on renderings, but there are instances where the glass is shown so light as to cause dark sashes to seem essential as a means of producing proper contrast. In "5," Figure 36, it will be noticed that the woodwork of the door is left light at the bottom where the glass is dark, but graded to dark at the top so as to count strongly against the light reflection. In "9," Figure 37, the sashes are in shadow and consequently dark, but the glass here is catching a strong reflection of light, as in the previous example. It perhaps seems a bit extreme to leave the glass as white as it is in this sketch and in the doorway at "13" on the same sheet, hut an effect of transparency is obtained in this way, and the light tone of the glass pleasingly breaks up the monotony of the shadow. Often, however, the glass in such windows is shown very dark, this being a matter of choice, as both conditions are found in actual buildings.
In most drawings of windows the shadows cast by the frame and by the sashes on the shades and curtains are made quite prominent, and this often adds greatly to the effect, and it is well as a rule to emphasize the shadows of the shutters also. There is another point worth considering and this is that if there is a large dark shadow near the top of a window it is best not to have a similar dark tone at the bottom, as such duplication may injure the result.