III
ILLUSTRATIONS
In technical work such as ours the illustrations are of two classes: (1) line drawings; (2) photographic or halftone illustrations.
Line Drawings.—Copy for line drawings should be made two to three times the dimensions of the completed illustration. The weight of line, and especially the lettering, should be carefully worked out to give desired results. The following illustrations, taken from "Engineering Drawing," by Thomas E. French, will serve as a guide to the draftsman preparing these illustrations. We suggest, however, that when the completed copy for a few characteristic illustrations is ready, the author send the samples to us in order that we may determine their suitability or even, if desirable, reproduce the samples in order that the author may examine the results with us. When difficulty is encountered in securing suitable lettering, which will give a finished appearance to the illustrations, we are willing to accept the drawings with the lettering penciled in. We, in turn, engage draftsmen, who are experienced in lettering for reproduction, to finish the work. As this often leads to errors, however, we prefer the completed drawings ready for reproduction.
Line drawings from periodicals, catalogues and other publications can be reproduced direct without material reduction in size, when the copy is suitable for the book, and, of course, when permission to reproduce has been secured by the author.
Halftone Illustrations.—Halftone illustrations can be made satisfactorily only from photographs or wash drawings. Photographs on a high-finish or glossy paper produce the best results. We cannot produce good results by making a halftone from a halftone print. A halftone engraving is photographed through a screen, and when we undertake to reproduce a halftone from a halftone print we throw one screen upon the other. In rare cases passable results can be obtained in this way, but such copy should be used most sparingly.
Drawing for one-half reduction.
One-half reduction.
If photographs are unmounted, they should not be mounted or pasted on sheets of paper. Smoothly mounted photographs present no difficulties to the engraver.