E.C. Lyons Roulettes are designed to be used in intaglio printmaking processes. When the rotating drum at the head of the tool is pushed over the plate, it stipples the ground with dots or lines. Acid will bite through these small impressions, creating dimples in the surface of the metal, which will then hold ink and appear darker in the finished print.
The density of lines or dots an engraving roulette will produce is expressed in its DPI rating. A higher DPI indicates the lines or dots made by a roulette as it passes over the face of the plate are closer together. This is a medium gauge line roulette of 65 DPI.