The most popular design file format is the STL file. And although it’s not very tricky to create high quality STL files for 3D prints, it’s not easy as well.

A file with .stl extension is a 3D graphic file native to Stereolithography technology. Stereolithography is basically a type of 3D printing technology to create 3D models.

Part of this is due to shortcomings in the STL file format. There’s a newer format available, 3MF, and Josef Prusa and Jakub Kočí would like you to start using it .