3D printing is so slow that printing reasonably sized objects requires printing overnight. Comparable to punched card systems in computing. However, as we moved towards faster processing in computing, we discovered that speed does not only allow to achieve more in less time, but also allows for interactive use (batch system -> command line -> direct manipulation). In the same manner as we directly manipulate digital data with out hands (touch screens), we also want to directly manipulate physical matter with our hands. For this, matter needs to change quickly, i.e. needs to be refabricated instantly.