You can download 3D files from Thingiverse or create your own design in Tinkercad. An .STL file is the most common file type used for 3D printers. You can print files from many other sources, just be sure that you are able to export or save as a .STL file. Both Thingiverse and Tinkercad are browser-based. You can download from both at the library OR bring your files with you on a flashdrive.