In the world of 3D printing, choosing the right file format is a crucial step in guaranteeing the quality and efficiency of your prints. But a multitude of formats available, it can be difficult to know which one is best suited to your project.
In this article, we’ll explore the file formats most commonly used in 3D printing: STL, OBJ, AMF, 3MF, and STEP, detailing their advantages and disadvantages to help you make an informed choice. Let’s dive in!
STL: Indispensable, but With Limits
The STL format, an acronym for “stereolithography”, is probably the best known in the world of 3D printing. Dating back to 1987, this format has become the standard thanks to its simplicity and universal compatibility. STL works by dividing the surfaces of a model into triangles, a process known as tessellation. This makes the format extremely practical for most CAD software and slicers.
However, this simplicity comes at a price. STL is not ideal for complex geometries, such as curves and holes, which may appear as visible polygons when printed. What’s more, the lack of specification of units of measurement can cause scaling problems when preparing the model for printing. Finally, STL files are often prone to errors such as internal intersections and non-manifold edges, which can compromise print quality if not corrected beforehand.
The same 3D model exported in STL or 3MF will not take up as much storage (photo credits: Prusa).
When to use it? STL remains the preferred choice for simple projects where compatibility with various software packages is essential. It is particularly suitable for beginners or for prints without complex geometric requirements.
OBJ: The Versatile Alternative
The OBJ format, although less popular than STL, offers additional features that can prove invaluable for more complex projects. Originally developed for 3D animation, OBJ can store additional information such as textures, materials and colors. This makes it particularly suitable for models requiring greater visual detail.
The OBJ format allows multiple colors to be specified in a single file (photo credits: Prusa).
One of OBJ’s main advantages is its ability to handle more complex geometries, using not only triangles, but also polygons and quadrilaterals. However, this wealth of functionality translates into larger files and often requires additional files to manage materials and textures, which can complicate the printing process.
When to use it? The OBJ format is ideal for projects where visual details such as textures and colors are important. It is also suitable for models with complex geometries that the STL format cannot handle well.
Contrary to the visual defects that may be present in STL files, OBJ files are generally of higher quality
AMF: The Forgotten 3D Printing File Format
The AMF format, or Additive Manufacturing File, is a modern evolution of the STL format, designed to overcome its limitations. Launched in 2011, AMF can store complex information such as color, material and lattice structures in a single file, while offering enhanced accuracy thanks to curved triangular tessellations.
Despite its advantages, AMF has yet to gain widespread acceptance in the industry. It suffers from a lack of compatibility with some older software, which limits its adoption.
Modeling is a crucial step in 3D printing, and choosing the right file format to export your models is just as important in the additive manufacturing process.
When to use it? If you’re working on a project requiring precise and varied information (materials, colors), and your software supports it, AMF can be an excellent option.
3MF: The New Standard in the Making for 3D Printing File Formats
The 3MF format, developed in 2015 by a consortium of leading companies, aims to become the new standard for 3D printing. Similar to AMF in terms of functionality, 3MF is designed to be more widely accepted and is already supported by a growing number of software and hardware products.
The 3MF format prevents errors in the 3D model (photo credits: Prusa)
3MF is an open-source, standardized format for storing complex models with precise information in a compressed, human-readable file. It also incorporates safeguards against common modeling errors, making it a print-ready format right from the start.
When to use it? The 3MF is an excellent choice for users looking to take advantage of the latest advances in 3D file formats. It is particularly suited to complex projects requiring high precision and compatibility with the latest technologies.
STEP: The Swiss Army Knife of CAD Formats
Finally, the STEP format, or Standard for the Exchange of Product Data, is widely used in CAD and engineering. Unlike other formats, STEP is not specifically designed for 3D printing, but it plays a crucial role in data exchange between different CAD systems.
STEP is a very useful format for sharing files between different 3D modeling software programs
STEP is capable of storing not only geometry, but also product structure, assemblies and metadata. However, it is not optimized for 3D printing, and may contain superfluous data that complicates the process of preparing the model for printing.
When to use it? STEP is ideal for projects involving complex assemblies, or requiring interoperability between different CAD programs. It is also useful for editing CAD files prior to printing.
Choosing the right file format for 3D printing depends on many factors, such as the complexity of the model, the visual detail required, and compatibility with the software used.STL remains the default choice for simple models and maximum compatibility, while 3MF is emerging as the future standard for more complex projects.The OBJ and AMF formats offer advanced functionality for those who need it, and STEP is indispensable for complex CAD projects.
Which file format do you prefer for your 3D prints? Let us know in a comment below or on our LinkedIn, Facebook, and Twitter pages! Don’t forget to sign up for our free weekly Newsletter here, the latest 3D printing news straight to your inbox! You can also find all our videos on our YouTube channel.