This article covers a feature introduced in SketchUp 2018. For help working with STL files in earlier versions of SketchUp, see 3D Printing a Model. In SketchUp, you can import and export STL files, which are used in 3D printing. As explained in 3D Printing a Model, for a SketchUp model to become a successful 3D printout, the model needs to meet certain criteria, such as having a base and a volume and being a solid.
Tip: Inserted SketchUp files can now contain Dashed Lines, to learn more about managing those new line types with inserted files, see Working with SketchUp Dashes in Imported Models After you work hard to create and polish a LayOut document, you want your document to go out into the world and make its mark. You can present your work on-screen, but that isn’t always enough.