Page:Pattern design - a book for students treating in a practical way of the anatomy, planning & evolution of repeated ornament.djvu/95

87. DIAGRAM SHOWING MECHANICAL RELATION OF VARIOUS PLANS.

be executed, may be set down as directly due to working on the lines of the diamond. A designer does not, except in certain deliberately formal patterns, keep his design within the lines upon which it repeats. But he has them always in view; and he does not stray from them so far that it ceases to make a difference what lines he works on. The advantage of setting out a drop design upon the plan of the diamond is, that the simplicity of the four straight lines enables him to keep more clearly in view than the other lines upon which the drop is worked, the ultimate relation of the parts of his design, and the order in which they will recur. Perhaps the most conspicuous advantage of the drop repeat is that it enables one to perform the apparently impossible feat of designing a pattern twice the width of given material, which yet works out perfectly as a repeat within its limits.

Working on the lines of the diamond, it is easy to do this. You have only to subdivide the area of your square repeat as here shown (88), (it might just as well have been a parallelogram as a square) so that two smaller divisions a and v together equal the larger ^. Then if you transpose the smaller parts a and v so that together with •^, they form a squat diamond twice the width of the original square, you

88. Diagram showing division of square repeat into three parts.

89. Diagram showing transposition of parts of square to form wide diamond.