What Is the Print Thin Walls Feature in Cura? Explained

While the print thin walls feature has a pretty self-explanatory name at first look, understanding the exact details of how enabling this feature will change the way that Cura generates the G-code file from your 3D model is a bit more complicated than the name lets on, with many different possible scenarios occurring based on how you configure some of the other print settings.

In this guide, we will explain the purpose & functionality of the print thin walls feature in Cura and discuss the cases where it can become necessary to activate this feature to make it possible to print parts of your 3D model that otherwise wouldn’t be possible.

What Is the Print Thin Walls Feature in Cura?

In essence, the print thin walls feature modifies Cura’s behavior when generating walls that are lower in thickness than a certain threshold determined by the line width (or wall line width if configured separately) value, making it possible to print walls that Cura would otherwise remove under normal circumstances.

When the print thin walls feature is inactive, you’ll find that Cura removes any wall with a thickness lesser than half of the line width value you’re using (you can check from the Preview tab) and, as a result, your 3D printer won’t include such walls on the printed part.

For instance, in the example 3D model below, where the wall on the top-left corner has a thickness of 0.05 mm, setting the line width value to 0.1 mm (or lower) will result in the wall appearing on the preview without any problems, as the wall will be thicker than half of the line width in this case, which makes it eligible for printing.

cura 0.05 mm wall present with adjusted line width


On the other hand, when you set the line width value to be slightly higher, such as 0.11 mm, which causes half of the line width (0.055 mm) to be larger than the thickness of the wall (0.05 mm), you’ll find that Cura completely removes this wall and causes it not to be printed anymore.

cura 0.05 mm wall removed due to line width


Now, when you activate the print thin walls feature, all the behavior we have previously talked about will completely change, and Cura will decide whether it will print a thin wall or not by comparing the wall’s thickness to the minimum feature size value instead of half of the line width value.

In the case where the thickness of the wall is smaller than the minimum feature size value, you will notice that Cura completely removes the wall once again when looking at the Preview tab, meaning that your 3D printer won’t be printing this wall regardless of the line width value you’re using.

Continuing the example from earlier, where we had a 0.05 mm wall at the top-left corner, we can observe that the wall has disappeared after setting the minimum feature size value to 0.06 mm.

cura minimum feature size removed wall


On the other hand, in a scenario where the wall’s thickness is larger than the minimum feature size value but smaller than the line width value, its thickness will be specified by the minimum thin wall line width value instead of its original size, which can even cause a wall that’s supposed to be thinner than others to end up thicker based on the configuration.

So, in an example where the minimum thin wall line width value is 0.6 mm, the minimum feature size is 0.05 mm, which would allow us to print the 0.05 mm wall on the top-left corner, and the line width value is 0.1 mm, which would make it so that our wall is thinner than the line width, we will observe that the wall that originally had a thickness of 0.05 mm ends up being printed with a thickness of 0.6 mm instead.

On the other hand, the 0.1 mm wall right next to it, which was originally larger than the 0.05 mm wall on the top-left corner, will be printed at its original thickness of 0.1 mm due to it not being thinner than the line width like the 0.05 mm wall is, and not be affected by the minimum thin wall line width value.

cura minimum thin wall line width example


Finally, if a wall’s thickness is larger than the minimum feature size value and the line width value, your 3D printer will print it at its original size without any modifications, which is the standard case.

When to Use the Print Thin Walls Feature in Cura?

As the print thin walls feature, as we have discussed earlier, makes it possible to print walls that Cura would otherwise ignore due to them not having sufficient thickness for optimal printing, it would be beneficial to activate this feature in scenarios where you absolutely require your 3D printer to print such walls, regardless of the quality implications.

An example for such a scenario would be the presence of text made up of thin walls, which would effectively be vital for the part you’re printing to be complete due to the text not being some minor detail that won’t make much of a change if it’s missing from the printed part.

cura minimum feature size letters disappear


By using the print thin walls feature and adjusting the minimum feature size value accordingly, you can get your 3D printer to print the text, and even though it’s possible for there to be a considerable loss of quality based on how thin the walls actually are, which would make it harder for your 3D printer to print them accurately, this would still make it possible to make an attempt at printing the 3D model fully intact.

cura minimum feature size letters fixed


Additionally, in cases where you don’t need the walls to be as thin as they were designed originally, you can always make use of the minimum thin wall line width feature to increase the thickness of the thin walls, which will allow your 3D printer to have an easier time printing them in a higher quality.

Conclusion

While we can consider print thin walls to be a niche feature that you most likely won’t end up using too frequently, it’s also one that will save you a lot of time in cases where the model you will be printing has walls that are too thin, especially considering that the only solution to print them without this feature would be to modify their thickness in CAD software manually.

That being said, as the behavior of the print thin walls feature isn’t as straightforward as simply making all the walls printable, regardless of their thickness, understanding how this feature functions and how you can customize its behavior through other parameters, such as minimum feature size, is vital to ensure that things work as intended.