What Are the Disadvantages of STL Files?

If you work with 3D printers, you've likely used STL files a lot. For 3D printing, these are the most popular file types. They work with almost all slicers and printers. This is one reason they were so well-known.

There are some problems with STL files, though. A lot of people, both new and experienced creators, have trouble with them. There are some problems with how the file saves data. Some of them make it harder to change or print. We will talk about the most significant issues with STL files and how to fix them in this guide.

1. STL Files Cannot Store Colour or Materials

The fact that STL files only store the shape of an item is one of their main flaws. The file uses many small triangles to represent the model's surface. The printer can use these shapes to determine what the object looks like.

You can't store details about colour, texture, or materials in an STL file, though. If you use more than one colour in your model design, you will lose that information when you save it as an STL file. Textures and other special surface features have the same issue.

Because of this, STL files aren't as useful for making complicated models that need different colours or materials.

How to Overcome This Problem?

When colour or materials are important, experts say to use newer file types. Some file types, like 3MF and OBJ, can hold extra data like colours, patterns, and material data.

It's best to use CAD software to make your model and save the source file. You should only export the STL file when you are ready to slice and print the model.

Ultimaker Cura is a piece of software that can help with this process. It works with many file types, such as STL, OBJ, and 3MF. When working with printers that are compatible, the software also lets you set colours and materials. It is easier to work with models that need more than just simple geometry when you use modern slicers like this one.

2. STL Files Are Difficult to Edit

One more problem that often happens with STL files is that they are hard to change. When you use CAD software to make a model, it has a lot of information about the plan. This includes sizes, shapes, curves, and the background of the design.

We lose all of this information when we save the model as an STL file. The model turns into a mesh of triangles. It can be hard to change the style later because of this.

When working with a triangle mesh, even simple things like changing the size of a hole or fixing it can get tricky.

How to Overcome This Problem?

The experts say that you should always save the original CAD drawing file. This lets you easily make changes without changing the mesh when you go back.

You can use mesh editing tools if you only have the STL file. Autodesk Meshmixer is a tool that both amateurs and pros like to use. You can easily fix meshes, combine models, and change STL files with this tool. Other tools make meshes easier to work with or turn them into customisable surfaces. To make working with STL files easier, you can use special tools for changing meshes.

3. STL Files Can Become Very Large

Also, STL files can get very big if the model has a lot of curves or areas with lots of details. We show curves with a lot of small shapes. The model is more detailed when there are more circles. But this makes the file bigger as well. If you have a very big STL file, it may slow down your slicer software and take longer to process the model.

How to Overcome This Problem?

When making STL files, experts say to change the export resolution. It is usually possible to change the number of triangles used in a CAD tool.

Cutting down on the number of triangles can make the file much smaller while keeping the print quality pretty much the same. Removal of useless triangles by mesh optimisation tools can also make the model simpler.

To do this, Blender is a useful tool. Blender has strong tools for mesh decimation that lower the number of polygons while keeping the shape of the model the same. A lot of artists clean and improve STL files with it before they slice them.

4. STL Files Often Contain Mesh Errors

One more problem with STL files is that they might have mesh mistakes. Models that you grab from online libraries often have these kinds of mistakes.

Common problems include holes in the mesh, surfaces that meet, or surfaces that are pointing in the wrong direction. If these things are wrong, the slicer might have trouble processing the model properly.

The printer may sometimes give you strange results because the software doesn't understand the shape correctly.

How to Overcome This Problem

One helpful tool is the Magic Fix feature in SelfCAD. This tool scans the entire STL model and automatically repairs common problems such as holes, non-manifold edges, and broken surfaces. Instead of manually fixing every issue, the software performs the repair process in seconds.

This can save a lot of time, especially when working with downloaded models that contain many hidden mesh problems. After running the Magic Fix tool, the model becomes watertight and ready for slicing and printing.

Using automatic repair tools like this helps ensure that your STL files print correctly and reduces the chances of failed prints.

5. STL Files Do Not Store Units

Another technical problem with STL files is that they don't have details about units. The file only keeps point values; it doesn't say if those values are in millimetres, inches, or centimetres.

So, when you open a model in a different program, it might look a lot bigger or smaller.

For instance, a model made in millimetres might open in inches, which would make it much bigger than planned.

How to Overcome This Problem

Experts say that before printing, you should check the model's measurements in the slicer. SelfCAD’s online slicer makes it easy to measure and scale models.

You can quickly change the scale before cutting the file if the size is wrong. It can also help to keep track of the units used during the planning process.

6. Curved Surfaces Can Look Rough

Since STL models use triangles to show surfaces, places that are curved are only close approximations. Shapes that are curved might look rough or faceted if the triangle sharpness is too low.

This issue stands out most in statues, models used for decoration, and organic shapes.

How to Overcome This Problem

When you send the STL file, raise the resolution to get a better surface. There are more circles and smoother curves when the resolution is higher.

But you shouldn't set the quality too high, as that will make the file bigger. Most of the time, the best results come from finding a quality setting that is just right.

7. STL Files Do Not Store Extra Information

The purpose of STL files is to keep things easy. They can't store any more knowledge about the model because it is so simple.

The file does not contain any important information, like the name of the creator, suggested print settings, or information about the material.

This can make it harder for people to work together when they share models.

How to Overcome This Problem

A lot of the time, experts can fix this problem by sending instructions along with the STL file. Designers can add notes about the materials, print settings, and suggested slicer setups.

SelfCAD helps overcome this limitation by allowing designers to set up printing parameters directly in the software before sharing the project. Inside SelfCAD, users can define slicing settings such as layer height, infill density, supports, and other print parameters. When sharing the project or preparing the model for printing, these settings help guide the person who will print the model.

In addition, SelfCAD allows designers to manage the model, make edits, repair geometry, and prepare the print in one workspace. This makes it easier to communicate how the model should be printed, even though the STL format itself cannot store extra information.

Conclusion

For many years, STL files have been the usual way to print things in 3D. They are simple, work with many slicers, and are simple to handle. This is why most 3D printing processes still use them today.

But STL files also have some problems. They can't keep information about colour or matter. They might be hard to change and have mesh mistakes. Also, they don't have any unit data or extra design information.

Luckily, these issues are simple to handle once you know what they are. You can avoid most STL problems by keeping the original design files, making sure the model is the right size, fixing meshes, and using new file types when necessary.