Repetier-Host is a free software from Germany that will slice a 3D model saved as a .stl file into gcode, the code that the 3D printers work from. Repetier-Host is basically a user friendly ‘front window’ that hosts two gcode slicer programs that are Slic3r and Skeinforge. Slicer3r is the easier to setup and this document covers how to set this up to work with paste materials, specifically clay on a Make your own Delta Ceramic 3D Printer.