Inventor

Once the part or assembly is created in 3D and is in positive space:
  1. Save Copy As
  2. Select STL
  3. Choose Options > Set to High (for highest quality surface)
  4. Enter File Name
  5. Save
For additional questions refer to your manual, MIS department or the Maker of the software: Autodesk

Select your CAD program in the pulldown menu to view the recommended settings for exporting an STL file