One of the main settings used to determine the quality and cost of your 3d print is layer height. A key principle of all 3d printing processes is that a part is made up of layers on top of each other in much the same way as a terraced landscape and the layer height is simply how high each of those terraced layers is. The thinner the layer, the higher the resolution the final print and the less obvious each layer will be.
The thinner the layers, the longer the part will take to print and its important therefore to consider what layer height you need in order to ensure you aren’t paying over the odds for a higher resolution print when the benefits will be minimal, or be disappointed with the result when you placed your order based on price at the expense of using a larger layer height.
In general, layer heights for plastic FDM printing using materials such as PLA, PETG and ABS are offered in three layer heights, 0.1mm (Fine), 0.2mm (Standard) and 0.3mm (Draft) resolutions. Some 3d printing processes such as SLA (resin) based printing can reach much lower layer heights making them ideal for detailed or intricate printing commonly used in small sculptures or jewellery. For large format printing we’ll sometimes consider using even higher layer heights of up to 1mm on the largest prints. In these cases, the sheer size of the model can actually mask the size of the layer height until you’re up close. With any 3d print, if you look close enough…. you’ll see the layers unless you apply some post processing such as sanding and painting of course.
4 things to consider when choosing layer height:
1 – Cost
As we’ve said, higher resolutions costs more to print, but it isn’t always necessary. The improvement by going to a finer layer height will be marginal on a print with lots of vertical faces vs a print with gradual slopes for example. A good rule of thumb is to start with 200 microns (0.2mm).
2 – End use
It might sound obvious, but if it is only a prototype for basic shape/fit requirements, does it really have to be the highest resolution possible? If it is for end use and might be painted, perhaps a lower resolution is ok and the time/effort is better spent on post-processing (filling, sanding and painting).
3 – Detail
If your part has many intricate details, it may be necessary to increase the resolution (choose a smaller layer height) in order to print these details. Where greater levels of detail are required such as dental 3d prints, jewellery or character modelling, a resin based SLA process may be best suited.
4 – Model Size
The larger the part the more likely it is you will be able to use a larger layer heights as the physical size of the print masks the layering effects. Obviously this isn’t always the case, but we recommend large format 3d prints have a minimum of 300 microns (0.3mm) layer height.
As you can see, there’s a few trade-offs and in many cases it comes down to cost, but we regularly help our customers to reduce 3d printing costs by working with you to understand the best trade-offs between printing method, layer height and finish required.