Thingiverse.com is the ultimate free 3D printing library, and most files are optimized for 3D printing. Thangs.com is a 3D print model search engine with both free and paid models and is another great resource for discovering 3D files.
To start creating your own designs or to modify a deign you found online, we recommend starting with Tinkercad, but Adobe Illustrator and Shapr3D are also good.
Vinyl Cutting
.png or .jpg
Most .png or .jpg images can be used with the CutStudio software. Ready-made designs optimized for vinyl cutting can be found on Google or Pinterest by searching "svg cut files."