A set of the three most common French curves, also known as a Burmester set. The bottom object is most commonly used for hyperbolas; the smaller one above it is suited for ellipses. The large one is used mostly for parabolas.[1]
A French curve is a template usually made from metal, wood or plastic composed of many different curved segments. It is used in manual drafting and in fashion design to draw smooth curves of varying radii. The curve is placed on the drawing material, and a pencil, knife or other implement is traced around its curves to produce the desired result. They were invented by the German mathematician Ludwig Burmester and are also known as Burmester (curve) set.
