Before a 3D model can be printed it must be sliced, meaning converted by software into printer instructions written in G-code, the instruction language shared by CNC machines and 3D printers. The software that performs this conversion is called a slicer, and popular options include Cura, PrusaSlicer, OrcaSlicer, Bambu Studio, and Simplify3D. Cura is a free, widely used slicer maintained by Ultimaker, while PrusaSlicer is an excellent open-source option from Prusa Research. Each slicer relies on profiles, which are pre-configured bundles of settings tuned for a specific printer and material, so beginners often only need to choose the right profile to get reasonable results.
Models reach the slicer as digital files in formats like STL, which is the long-standing standard for storing 3D mesh data; 3MF, a more capable modern format that can include color and metadata; and OBJ, which often carries color and texture information. Designers source models from repositories such as Thingiverse, the large free library that pioneered the format but has grown dated, and Printables, Prusa's quality-focused platform; Thangs, MyMiniFactory, and Cults3D are also widely used. For original designs, CAD tools are needed, with popular options including Fusion 360 (a powerful Autodesk package that is free for hobbyists), FreeCAD (an open-source parametric option), OnShape, Tinkercad (a beginner-friendly browser tool), Blender (an art-focused 3D modeler that can produce printable meshes), and SolidWorks. Parametric design uses dimensions that automatically update the model when changed, while mesh modeling manipulates polygons directly and is more common in artistic workflows.