Guilloche Spiral

This image was created with a technique based on guilloche curves—sinusoidal curves bounded by other curves. They are used in engraving as decorations and on banknotes to enhance security. In this technique, I embedded a linear spiral (r = θ) between two curves. The spiral is tangent to the inner curve at its beginning and to the outer curve at its end.

Here, I used a series of boundary curves, from the center outward: a point, a circle, a three-lobed rose curve, a five-lobed rose curve, a circle, and a square. The curves were sized such that each subsequent curve was tangent to the one before it (except for the inner circle). The effect was intended to be reminiscent of DaVinci’s “Vitruvian Man.” Two spiral arms suggest any of the two dichotomies that confront man: male & female, life & afterlife, good & evil, or maybe even the square & circle that surround DaVinci’s man. One arm begins on the right side in the center and the other ends on the left side in the center.