Illustrations, usually photographs or drawings, are used extensively in sets of instructions and manuals. To point out the important parts of an illustration, writers use callous, letters or words connected by lines to the relevant
part of the illustration. The following general guidelines explain how to make illustrations more effective Use illustrations to avoid lengthy discussions. A picture of a complex

  • pint will generally be more helpful than a lengthy description.
  • Use high-quality illustrations: make sure they cue clear, and large enough to be effective, and set oif by plenty of white space.
  • Keep the illustrations as simple as possible. Show only items essential for your discussion.

Photographs are difficult to use in technical reports because,’ in order to be reprinted, they must be converted to halftones. This process changes the photograph into a series of dots, which until recently only the printing press could reproduce. Computer technology has partially solved this problem with scanners, devices which convert photographs into halftones electronically. These expensive devices produce acceptable but low-quality halftones. A writer inserts a photograph into a scanner, which electronically  converts the photograph into dots. Using a scanner and an instant camera, many amateurs can produce acceptable halftone photographs in minutes. Drawings are easier to reproduce. A scanner will produce good reproductions of line drawings, since they do not have to be converted to halftones. Anyone with a scanner can easily convert. a line drawing on a sheet of paper into electronic dots.


A good photograph has these advantages: it duplicates the item discussed (so audiences can be sure that they are looking at what is intended), and it shows the relationship of various parts. The disadvantages are that it reduces a three-dimensional reality to two dimensions and that it shows . everything, thus emphasizing nothing. Figure 7.7 shows a skillfully “cropped” photograph. The original contained much more visual information, but the designer blocked out a great deal of it, simplifying it so it makes only one point.


Drawings, whether made by computer or by hand, can clearly represent
an item and its relationship to other items. Since details in drawings are


Cropped Photograph
Source: A manual by Jill Adkins. Reprinted by permission of MRM Elgin.

chosen selectively by the artist, the reader can focus on just the intended  object. The exploded view and the detail drawing are two commonly used types of drawings.

Exploded View As the term implies, an exploded view shows the parts disconnected but arranged in the order in which they fit together, as in Figure 7.8. Exploded drawings can show the internal parts of a small and intricate object or explain how it is assembled. Manuals and sets of instructions often use ~xploded drawings with ‘named or numbered parts.

Detail Drawings Detail drawings are renditions of particular parts or assemblies. They are used in manuals and sets of instructions, usually in one of two ways. Drawings can function as an uncluttered, well-focused photograph, ‘Showing just the items that the writer wishes, They can also show cross-sections, that is, they can cut the entire assembled object in half, both exterior and interior. In technical terms, the object is cut at right” angles to its axis. A cross-sectional view shows the size and relationship of all the parts. Two views of the same object, front and side views, for example, are often placed beside each other to give the reader an additional respective of the object. (See Figure 7.9.)


Exploded View
Source:  Controls: Independent Study Workbook by John R. Mancosky. Used by permission of Micro switch and John R. Mancosky.