In 1970, Stella's work underwent an important change. His early canvases were flat and geometric, but he then switched direction and created a progression of series of highly engineered 3-D constructions. Stella's Shards series evolved from the Circuits series, both of whose dense and layered surfaces contain French curves, ship's curves, and the bendable flexicurve. The Shards works also contain the Pantograph (a draftsman's tool) and were constructed out of production scraps that were tilted into place. The focus of these works is a multi-layered background consisting of punctured planes. Perhaps the most remarkable aspect of the Circuits and Shards series is the dramatic force with which Stella paints the metal forms. Using wax crayons, transparent glazes and various texturing devices, Stella creates a dynamic variety of application and surface.