Things to know


Our 12 printing filament


Files used for 3D Printing

    3D printers require a specific input file type. Most use STL, short for stereolithography, which is an additive fabrication technology introduced by 3d Systems in the mid-1980s. While other AF technologies have emerged, the STL file format has remained the standard for 3D printing.

    STL files are representations of surface geometry in a triangulated format. While some are finding ways to add color information to specific triangles within the STL structure and creating new file types that represent these colors, true STL files do not contain any color information.
It is always a good idea to check the quality of an STL file before 3D printing it with an STL viewer at minimum. “Materialise’s Magics” software is the industry gold-standard in STL viewing and repair. There are other STL viewers available.

    Many CAD applications can export geometry to the STL format. You should be cautious when relying on the ‘raw’ export. When converting CAD files to STL files inconsistencies can appear in the STL file that will cause problems in 3D printing process. All of the triangles in a STL file have a front and a back, or inside and outside. The front of the triangle is called a normal, and normals need to point the same way, outward. This is what defines an object’s inside and outside. STL files exported directly from a CAD application tend to have inconsistencies in the normal directions. If the file is put into a 3D printer with inconsistent normals, there will be voids in the printed object.

    OBJ Files The file format is open and has been adopted by other 3D graphics application vendors. For the most part it is a universally accepted format. OBJ files are typically pretty versatile.
The OBJ file format is a simple data-format that represents 3D geometry alone — namely, the position of each vertex, the UV position of each texture coordinate vertex, vertex normals, and the faces that make each polygon defined as a list of vertices, and texture vertices. Vertices are stored in a counter-clockwise order by default, making explicit declaration of face normals unnecessary. OBJ coordinates have no units, but OBJ files can contain scale information in a human readable comment line.

    IGES Files is a file format which defines a vendor neutral data format that allows the digital exchange of information among Computer-aided design (CAD) systems.

Features that are supported for each 3D printing file format.

Format 3D Geometry Colors Textures
OBJ (Wavefront) Yes Yes Yes
PLY (Standford) Yes Yes No
STL Yes No No
OFF Yes No No
SKP (Sketchup) Yes Yes Yes
KMZ (Google Earth) Yes Yes Yes
3DS (3D Studio) Yes Yes Yes
AC3D Yes Yes Yes
ASE (3D Studio) Yes No No
DAE (Collada) Yes Yes Yes
MD2/MD3 (Quake) Yes No No
Q3O (Quick3D) Yes Yes Yes
COB (TrueSpace) Yes Yes No
DXF4 (AutoCAD) Yes Yes No
LWO (LightWave) Yes Yes Yes
IGES Yes No No
STEP (ISO 10303) Yes No No
VRML Yes Yes Yes
SCAD (OpenSCAD) Yes No No
ZIP3 Yes Yes Yes
RAR3 Yes Yes Yes
TGZ3 Yes Yes Yes