Layer height is one of the most significant parameters in 3D printing, responsible for determining how tall each layer of the 3D printed model will be.
While a simple parameter at its core, the fact that the optimal layer height depends on factors such as the nozzle size of your printer and the type of filament you’re using can make finding the correct value slightly challenging at times.
Since many enthusiasts struggle to find the correct layer height for printing with PETG in particular, usually after moving away from PLA for the first time, we decided to cover everything about finding the optimal layer height for PETG in great detail in this article.
So, what is the optimal layer height for PETG?
For a standard 0.4 mm nozzle, we recommend using a layer height of 0.24 mm to print PETG, which we can consider a balanced value for surface resolution and consistency.
While a lower layer height value produces better surface resolution, it usually creates consistency issues such as tearing and filament buildup on the nozzle, requiring further fine-tuning.
In the upcoming sections, we will take a deeper look at finding the optimal layer height for printing PETG, find out how you can calculate layer height for different nozzle sizes, and discuss how different layer height values impact your print.
What Is the Optimal Layer Height for PETG?
Since layer height is a value that creates a trade-off between print quality and consistency, we can’t deny that preference plays a significant role in optimal layer height selection.
That being said, our experiments have shown us that using a layer height value of 0.24 mm with a 0.4 mm nozzle for printing PETG creates a good balance between quality and consistency, producing models that are both aesthetically and functionally satisfactory.
While experimentation allowed us to finalize it, we reached this value through a series of calculations that you can also use to calculate the optimal layer height value for the nozzle size you use.
The layer height value should be a multiple of the value you get by taking the multiplicative inverse of the division of micro-steps per millimeter by the number of micro-steps in a full step, which will allow you to avoid micro-stepping.
For instance, for a motor, such as the NEMA17 motor in Ender 3, that uses 400 steps per mm with 16 micro-steps in a full step, the value would be 1/(400/16) = 0.04 mm.
The layer height value must be between 25% and 75% of the nozzle size.
For instance, with a 0.4 mm nozzle, the layer height value you use must be in the range of 0.1 mm and 0.3 mm.
Following the examples for these two rules, there would be five different layer heights that we can use, which are 0.12 mm, 0.16 mm, 0.2 mm, 0.24 mm, and 0.28 mm.
The next step is to start experimenting with the highest layer height value (as it’s the most consistent to print) and move downwards until you experience issues to find the most optimal layer height for the best surface resolution and highest consistency possible.
While higher layer height values are suitable for parts that have a functional purpose, those who need the maximum aesthetical quality will have to keep moving down to lower values.
Please note that moving down to lower values requires a great deal of effort and time for fine-tuning settings such as print and cooling speeds, print temperature, retraction, and many more.
What Is the Optimal Initial (First) Layer Height for PETG?
While a part of the layer height setting, the initial layer height is a whole different topic of its own due to bed adhesion becoming a factor.
We recommend using an initial layer height of 0.28 mm for printing PETG with a 0.4 mm nozzle, the maximum layer height value within multiples of 0.04 mm.
To calculate the first layer height for different nozzle sizes, you can use the formula of nozzle size * 0.75 and round it down to the closest multiple of 0.04.
Considering that bed adhesion is one of the most common issues with printing PETG, the benefit of a thicker first layer is undeniable.
While thinner layers can cool down too quickly and contribute to bed adhesion issues, a thick layer allows more heat to flow through the model, giving it sufficient time to adhere to the bed.
Even though there are mixed opinions about the first layer, with some members of the community swearing by squishing the layer through lower height values, our experimentation has shown us that a high layer height value does a fantastic job for bed adhesion.
What Are the Effects of Layer Height on Printing PETG?
The effects of layer height on printing PETG are significant but also easy to understand.
In a nutshell, the surface resolution of the print, the print time, and the chance of inconsistencies (such as tearing) showing up on the print increases as the layer height value gets smaller.
While there is no issue with using higher layer height values for a more consistent printing experience for models that will be used for functional purposes, lower layer height values are vital for aesthetical models where the surface resolution needs to be as high as possible.
What Are the Effects of Initial (First) Layer Height on Printing PETG?
While the effects of initial layer height differ from layer height, there isn’t a lot of complexity involved in this case either.
As a rule of thumb, a thicker layer will improve the bed adhesion due to the layer cooling down slower than a thinner one, giving the plastic enough time to adhere to the surface as well as possible.
Since the initial layer of the model sets the foundation for the whole object, the initial layer height is one of the most significant factors in determining how successful your print will be.
There is no denying that finding both the optimal layer height and the optimal first layer height is vital to conducting the 3D printing process successfully with PETG filament.
To quickly recap, our recommendation is to use a layer height value of 0.24 mm, and an initial layer height value of 0.28 mm for printing PETG with a 0.4 mm nozzle.
That being said, as models that lean more towards aesthetical usage require lower layer height values for better quality, a comfortable layer height value may not always be the answer.
In either case, you should obtain a good level of bed adhesion and strike a balance between print quality and consistency with these values, and experiment further depending on your needs.