The most common and universal file formats for 3D printing are STL and VRML. STL stands for “stereolithography” – it is a 3D rendering that contains only a single color. This is typically the file format you would use with desktop 3D printers. VRML (“vermal”, .WRL file extension) stands for “Virtual Reality Modeling Language” – it is a newer digital 3D file type that also includes color, so it can be used on desktop 3D printers with more than one extruder (i.e. two more nozzles that each can print with a different color plastic), or with full-color binder jetting technology.
Additive Manufacturing File Format (.AMF) is a new XML-based open standard for 3D printing. Unlike STL, it contains support for color. They can also be compressed to about half the size of a compressed STL file. AMF is not widely used at present, but in future we would like to add this an option for uploading and downloading files to and from the NIH 3D Print Exchange.
Another file format input for 3D printers in GCode. This file contains detailed instructions for a 3D printer to follow for each slice, like the starting point for each layer and the "route" that the nozzle or print head will follow in laying down the material. In addition, 3D printer manufacturers may have their own proprietary input file formats that contain instructions specific to the methodology for that make or model, and that are compatible only with that manufacturer's software. This does not create a barrier to printing with these machines, as the proprietary file format is generated from the user's own STL or WRL file. Some examples include the .form file, used with the PreForm software for Form1 printers, or the .zpr format, proprietary to the ZPrint and ZEdit software used with ZCorp binder jet printers.