What is the most common file type for exporting a part to a 3D printing slicer program?

The most common file type for exporting a part to a 3D printing slicer program is .STL. The STL (Stereolithography) format has become a widely accepted standard in the 3D printing industry due to its simplicity and compatibility with most slicer software. STL files store information about the surface geometry of a 3D object in a straightforward, triangulated format, making them easy for slicers to interpret and use for layer slicing.

This format is specifically designed for 3D printing applications, which is why it is often the preferred choice among users looking to prepare their models for additive manufacturing. While other formats like .OBJ, .DXF, and .3MF also have their uses, they are not as universally accepted in the 3D printing workflow as .STL files. .OBJ files can contain additional information such as color and texture, which is not usually required for slicing. .DXF is typically used for 2D designs and CAD programs, and .3MF, while it offers advantages like reduced file size and support for color, is not as commonly used as STL files at this time.