Configuring Layer Height & Initial Layer Height – PLA, PETG, ABS & More

Layer height and initial layer height are two of the main slicer settings you will need to adjust correctly for a successful print, with the former determining how thick each layer will be, which considerably impacts factors such as print quality and printing time, and the latter determining the thickness of the first layer in specific, which plays a critical role in ensuring that the bed adhesion is strong enough.

In this guide, we will explain how you can configure the layer height and initial layer height values to be optimal when printing with any of the widely used filament types ranging from PLA to ABS, which will allow you to adjust the visual quality to strength balance of your 3D model and ensure that you don’t have any issues regarding bed adhesion.

Configuring the Layer Height Value

The math is pretty straightforward when it comes to configuring the layer height value for printing PLA, PETG, ABS, TPU, or practically any other filament that comes to mind, as there’s a clear formula to follow that you can utilize to find the layer height values that will work based on your nozzle size.

cura layer height description


To apply the formula that will provide you with the optimal layer height range for the size of the nozzle you’re using, you will first need to multiply the size of the nozzle attached to your 3D printer by 0.25, which will give you the lower bound of the layer height range, and then multiply the nozzle size by 0.75 after, which will allow you to calculate the higher bound.

So, as an example, if you’re using a standard 0.4 mm nozzle with your 3D printer, the optimal layer height range in your case would be 0.1 mm (0.4 * 0.25) to 0.3 mm (0.4 * 0.75), meaning that any layer height value in this range should produce a successful print for the nozzle you’re using with no problems such as nozzle clogging or under-extrusion stemming from the usage of an incorrect layer height value.

While not a complete necessity, the next step to take when configuring the layer height value as optimally as possible is to find the magic number of your 3D printer, which refers to the minimum distance that the Z-axis of your 3D printer can move with each step of the stepper motor, and to ensure that the layer height value is a multiple of this number.

This way, with the layer height value set to a multiple of the magic number, your 3D printer will be able to conduct the printing process by using the exact layer height you have specified without any mechanical difficulties involved in traveling the correct amount of distance and ensure that you don’t come across any dimensional inaccuracies as a result of the Z-axis movement undershooting or overshooting the layer height due to such constraints.

Following the example of a 0.4 mm nozzle from earlier, if we assume that you’re using an Ender 3, which has a magic number of 0.04 mm, we would need to find the multiples of 0.04 mm between 0.1 mm and 0.3 mm for the optimal layer height values, which would leave us 0.12 mm, 0.16 mm, 0.2 mm, 0.24 mm, and 0.28 mm as viable candidates.

Now that you are finished with the calculations and have a list of viable layer height values available, it’s time to discuss the process of choosing the one that you will be using for your prints as the last step of layer height optimization, where the decision primarily comes down to your needs and the purpose of your project.

In essence, when using layer height values that are closer to the top end of the range, the primary benefits you will notice are an overall increase in strength due to there being fewer weak points that reside in between layers and shorter print times due to your 3D printer being able to complete the print without having to perform a lot of horizontal movements, but at the expense of visual quality and detail.

On the other hand, as you get closer to the lower end of the range of layer height values that are available to you, you will notice a considerable increase in the visual quality and smoothness of your prints due to there being less stair stepping and smaller gaps between the layers, and also more detail on the top and bottom sides of the print with the layers getting thinner, but this time, at the expense of strength and time.

With these advantages and disadvantages in mind, for both the usage of high and low layer height values, our recommendation would be to lean toward the lower end of the range (such as 0.12 mm and 0.16 mm in our example) for prints such as figurines where the visual quality is the most vital factor, the higher end of the range (such as 0.24 mm and 0.28 mm in our example) for prints such as prototypes where quick print times will come in handy, and the middle of the range (such as 0.2 mm in our example) for general purpose printing.

Configuring the Initial Layer Height Value

Similar to configuring the layer height, configuring the initial layer height value also follows a simple rule you can utilize for your prints, which will practically ensure that you never have issues related to bed adhesion due to the first layer being thinner than it should be for it to adhere strongly enough to the print bed.

cura initial layer height


In the case of configuring the initial layer height, the first step of the method we recommend using to find the optimal value is multiplying the nozzle size of your 3D printer by 0.75, which practically is the same number as the upper bound for the range of suitable layer height values that we have discussed in the earlier section.

As an example, for a 3D printer with a nozzle size of 0.4 mm, the initial layer height value you would obtain from the formula would be 0.3 mm (0.4 * 0.75), and for a 3D printer with a nozzle size of 0.6 mm, the formula would give you 0.45 mm (0.6 * 0.75) instead.

Once you have this value at hand, the next step to take, as we have discussed in the previous section, is to find the magic number of your 3D printer, which refers to the minimum distance that the Z-axis of your 3D printer can move with each step of the stepper motor, and to round the value you have found in the previous step to be a multiple of this magic number.

So, for instance, if you’re the owner of an Ender 3, which has a magic number of 0.04 mm, with a 0.4 mm nozzle attached, you would need to find the closest multiple of 0.04 to 0.3 without exceeding it, which, in this case, would present you with an initial layer height value of 0.28 mm that you can enter into your slicer for an optimal configuration.

While the initial layer height value doesn’t require case-by-case adjustment as the layer height value does, since its primary responsibility is to ensure that the first layer sticks strongly enough to the print bed, which every print requires regardless of its purpose, it can become necessary to reduce this value slightly (or utilize the horizontal expansion feature to compensate instead) in cases where the first layer ends up sagging due to the thickness being way too high.

Conclusion

Since there isn’t a whole lot that goes into finding the optimal layer height and initial layer height values, correctly configuring these two parameters should be a quick and easy process for the most part without much room for error as long as you stick to the tried and true formulas for both.

That being said, as you should be configuring the layer height according to the purpose of the part you’re printing and follow the initial layer height value up accordingly, it’s always a good idea to double-check the initial layer height and layer height values you’re using before starting a print, as you may want to make adjustments to them across prints.