Thus, instead of a truly smooth surface, an STL object is composed of a high number of very small, non-overlapping triangles. It’s also one of the oldest, developed in the 1980s and was originally meant to simplify the transfer of data from 3D CAD models to a 3D printer.Ī characteristic of the STL file format, which makes it one of the simpler options, is that it approximates a 3D surface as a triangular mesh. STL stands for “Stereolithography” and is considered one of the simplest 3D file formats. Should you find yourself with an STL file format that you’d like to tweak and play around with, what software should you use? What exactly is the STL file format, and why is it so important? What is the STL file format? Despite its ubiquity, STL files are notoriously difficult to edit. The community of 3D printing and modeling may have become much larger in the past few years, but most 3D models shared online nowadays are limited to a few file formats. 3D Insider is ad supported and earns money from clicks, commissions from sales, and other ways.