The process of 3D printing begins with a computer file of a 3D model. This file is created using CAD software and is exported in the .stl or .obj file format. Files can also be created by capturing existing objects using a 3D scanner or a series of photographs. 

It is also common for people to freely share files that they have created and you can obtain shared files on websites like thingiverse.com. 

Once the .stl file is created or obtained, it is processed through additional software to prepare the file for printing. This software is sometimes called slicing software. In the Library, we use the Cura software that is compatible with our Ultimaker 3D printers. The Cura software transforms the .stl or .obj file into a .gcode file which can be read by the Ultimaker. 

The .gcode file is saved onto an SD card and then put into the Ultimaker. Once the 3D printer is prepared for printing, it reads the .gcode file and builds your 3D model by adding very thin layers of plastic onto each other. This process is known as Fused Deposition Modelling or Freeform Fabrication. 

To learn about other 3D printing methods, refer to the 3D Printing Processes Guide from 3DPrintingIndustry.com.