AMF

AMF (Additive Manufacturing File Format) is an XML-based open standard for 3D printing, developed by ASTM. It extends STL by adding support for color, materials, textures, gradients, and repeating units, aiming to serve as a modern replacement for STL. It supports multiple geometric representations and allows embedding print-related metadata in the file.

Despite its technical advantages, AMF's ecosystem is far less mature than STL or 3MF: most slicers have incomplete support, and models may lose color or material information during toolchain transfer. The de facto modern standard in the 3D printing community today is 3MF, while AMF appears more in academic and early color printing scenarios.