STL property Leave feedback On this page STL property Definition: See Also STL property STL is a file format native to the stereolithography CAD software created by 3D Systems. Chuck Hull, the inventor of stereolithography and 3D Systems’ founder, reports that the file extension is an abbreviation for stereolithography. here. Definition: f STL See Also module groupdocs.metadata.common class FileType Was this page helpful? Not really Yes, thanks Any additional feedback you'd like to share with us? Skip Send Please tell us how we can improve this page. Skip Send Thank you for your feedback! We value your opinion. Your feedback will help us improve our documentation.