If you\u2019ve ever ordered 3D printing<\/a> or prepared a model for printing yourself, you\u2019ve almost certainly worked with STL files. The format appeared back in 1987 and is still the most common in 3D printing. But technology moves on: modern printers can print in several colours and different materials at once, and models keep getting more complex. That\u2019s why the 3MF format<\/strong> (3D Manufacturing Format) was created \u2014 a modern alternative to STL, developed by the 3MF Consortium specifically for additive manufacturing.<\/p>\n 3MF is an open, XML-based file format that stores not only a model\u2019s geometry but also information about colours, textures, materials and even print settings. In essence, one 3MF file can contain everything needed to reproduce a part exactly as the model\u2019s author intended.<\/p>\n To understand why 3MF is gradually replacing STL, let\u2019s look at the key differences between the formats.<\/p>\n STL files store geometry as a set of triangles, and each triangle is described separately \u2014 even if it shares vertices with its neighbours. This leads to a lot of duplicated data. The 3MF format uses an optimised XML-based structure with ZIP compression. In practice, this means a 3MF file can be 2\u20135 times smaller<\/strong> than the equivalent STL. For complex models with millions of polygons the difference is even more noticeable \u2014 instead of hundreds of megabytes you get a compact file that\u2019s easy to email.<\/p>\n An STL file contains no colour information at all \u2014 just \u201cbare\u201d triangles. If your model should be multicoloured or textured, that information has to be sent separately. The 3MF format supports full colour and textures<\/strong> directly in the file. This is critical for multicolour printing (for example, on printers with Bambu Lab\u2019s AMS system), where each part of the model can have its own colour or even a gradient.<\/p>\n Another significant advantage of 3MF is the ability to store material data. You can specify which part of the model should be printed in PLA and which in TPU or PETG. For multi-material printers this is a real breakthrough: the designer assigns materials at the modelling stage, and the slicer reads this information automatically. STL simply has nothing like it.<\/p>\n One of STL\u2019s biggest problems is that files often contain geometry errors: open surfaces, flipped normals, self-intersections and so on. Such errors may be invisible when viewing the model but cause artefacts during printing. If you\u2019ve ever had to prepare an STL file<\/a> for printing, you know how much time repairing such geometry takes.<\/p>\n The 3MF format has built-in validation<\/strong> \u2014 the specification requires the model to be a valid closed solid. Most programs automatically check for and fix typical errors when saving to 3MF. This greatly reduces problems at the slicing and printing stages.<\/p>\n Support for 3MF is quite broad today and covers most modern 3D printing tools:<\/p>\n3MF vs STL: a detailed comparison<\/h2>\n
File size<\/h3>\n
Colours and textures<\/h3>\n
Material information<\/h3>\n
Model integrity and error protection<\/h3>\n
Extra features of 3MF<\/h3>\n
\n
Which programs support the 3MF format?<\/h2>\n
\n