3D print quality is one of the most important aspects of 3D printing, especially when creating objects for aesthetic looks. Learning how to 3D print without getting layer lines is an important skill to have in your 3D printing journey.
To 3D print without getting layer lines, you should reduce your layer height and nozzle diameter to around
Unfortunately, it can be pretty difficult to get 3D prints that don’t show layer lines. I decided to do some research to 3D print without layer lines for the highest quality prints.
Keep on reading through this article for some great tips, tricks, and pointers to achieving this useful ability.
Why Do 3D Prints Get Layer Lines?
Some of the many reasons which can cause layer lines are listed below. I will be explaining all these reasons in the next section of the articles so, keep on reading.
- Using a large layer height
- Using a large nozzle diameter
- Looseness or slack in 3D printer parts
- Incorrect printing temperature
- Low quality filament
- Bad model orientation
- Printing in a cold room
How to 3D Print Without Getting Layer Lines?
1. Reducing the Layer Height
One of the best things that you can do to 3D print without getting layer lines comes down to your layer height. There aren’t really many ways around this in terms of improving your print quality to the point where you are getting a smooth exterior surface.
When you are 3D printing an object, you see that they are built up of several layers. The larger the layer, the rougher the feel and more visual the layer lines become.
You can think of it as a staircase. If you have very large steps, that’s a rough surface in terms of 3D printing.
If you have tiny steps, it’s going to be a smooth surface. The smaller the ‘steps’ or layer height in your objects the smoother it will be, up to the point where you can’t see the layer lines.
What you should do is:
- Reduce the layer height in your slicer
- Use the ‘Magic Numbers‘ which are now default in Cura (e.g. 0.04mm increments for the Ender 3)
- Run several test prints and see which layer height produces the least visible layer lines
- You may have to adjust your nozzle diameter and temperature to account for the reduction in layer height
I’ve written a detailed post about the ‘Best Layer Height for 3D Printing‘ which goes into how reducing your layer height makes the most significant difference in 3D printing without layer lines.
2. Adjust Nozzle Diameter
Following on from the previous method, if you want to reduce your layer height small enough, you may need to change your nozzle diameter to account for that change.
The general rule for nozzle diameter and layer height is that your layer height should be no larger than 80% of your nozzle diameter. It also works the other way where your layer height should, at minimum be 25% of your nozzle diameter.
I’ve been able to 3D print with my 0.4mm nozzle and get some great Benchy prints at a 0.12mm layer height, which presented a print which barely had any layer lines showing and was very smooth to the touch.
You’ll want to use a smaller nozzle if you are printing miniatures or just small objects in general which have a lot of detail. You can do an amazing job of 3D printing without layer lines with a small nozzle, which I’ve seen go down to 0.1mm.
- Adjust your nozzle diameter relative to your layer height
- Try out many nozzle diameters and see which one works best for your projects
- You can purchase a set of nozzles which range from 0.1mm to 1mm in nozzle diameter
3. Mechanical Issues
Even after reducing your layer height there are other factors which may hold you back from creating 3D prints without layer lines, one of these factors is mechanical issues which relates to the physical parts of your 3D printer.
Mechanical issues also include the surface in which you are printing on, any slack within the moving parts and so on. Many imperfects and defects in 3D prints arise from this factor, especially with vibrations from the movements of your printer.
I actually wrote an article about How to Fix Ghosting/Ringing in 3D Prints, which are wavy lines throughout your print exterior.
- First, I would put my 3D printer on a sturdy surface
- Implement anti-vibration mounts and pads to reduce these movements
- Make sure there aren’t any loose screws, bolts or nuts throughout your 3D printer
- Keep your lead screw lubricated with a light oil such as sewing machine oil
- Make sure your lead screw isn’t bent, by removing it and rolling it on a flat surface
- Ensure your filament is being fed through the extruder smoothly, and without obstructions
- Use Capricorn PTFE Tubing which gives a smooth, tight grip on extruded filament
4. Find Your Optimal Printing Temperature
If you’ve ever printed a temperature tower, you can see how small differences in temperature makes a significant difference. Having the wrong temperature can easily contribute to creating 3D prints that show layer lines.
Higher temperatures melt your filament quicker and make it less viscous (more runny) which can give you print imperfections. You want to avoid these imperfections if you are after some good print quality.
- Download and 3D print a temperature tower to find the optimal printing temperature for your filament.
- Each time you change filament, you should calibrate the optimal temperature
- Keep your surrounding environment in mind in terms of temperature, as you don’t want to 3D print in a cold room.
5. Use High Quality Filament
You’d be surprised how much the quality of your filament can make a difference in your final print quality. There are many users who have changed filament to a reliable, trusted brand, and seen their 3D printing experience really turn positive.
- Purchase some high quality filament, don’t be afraid to spend a little extra
- Order a number of highly rated filament and find the one which works best for your projects
- Get filament which has a rough texture like marble, or wood which hides layer lines better
The smooth filament will actually make the surface smooth, which will reduce the appearance of lines.
6. Adjust Model Orientation
Model orientation is another key factor that can help you in reducing the layer line in 3D printing. If you don’t know the optimal orientation for your models, this can result in layer lines showing up a lot more visibly.
It’s not as effective as reducing your layer height or nozzle diameter, but once you have implemented the previous factors, this one can give you that extra push for 3D prints without layer lines.
Another thing to keep in mind is the best resolution we can get in certain directions, whether it is the XY plane or the Z axis. The resolution in the XY plane is determined by your nozzle diameter because material is extruded in lines from that opening.
On the Z-axis, we are looking at each layer, or the layer height, which can go down as far as 0.07mm in most home-owned 3D printers, so that resolution is a lot finer than in the XY plane.
This means that if you want to reduce layer lines as best as you can, you want to orient your model in a way where the finer details are going to print along the vertical (Z) axis.
- You want to try to use an orientation which creates the most level planes rather than arching shapes
- The less angles in your model orientation, the less layer lines should show up
- It can be quite difficult to balance optimal orientation factors since there are conflicting orientations
An example would be a model of a sculpture, with facial features. You would want to print this vertically because the facial features require serious detail.
If you 3D printed this diagonally or horizontally, you would find it hard to get that same level of detail.
7. Temperature Fluctuations
Avoiding temperature fluctuations is another important factor, especially when printing materials like ABS.
Filament reacts to heat by expanding and shrinking, so if you have wide enough temperature fluctuations, you can reduce your print quality, where layer lines may be more visible.
As they would not be getting the right temperature to cool down, and the surface would stay rough with visible lines.
- As mentioned previously, ensure your printing environment has a steady running temperature that isn’t too cold.
- Check that your PID controller is working, which controls temperature fluctuations (shown in the video below)
If the temperature fluctuation problem gets solved, you will start to see more smooth prints with less visible line patterns.
This can happen when the temperature is too high and the filament is melting more than usual. Another cause is from your extrusion multiplier or flow rate being changed, at a higher value than normal.
Anything that can cause your filament to be pushed faster, or more liquid can lead to over-extrusion which doesn’t fare too well for your 3D print quality, and especially 3D printing with no layer lines.
This over-extrusion will start depositing more filament on the print surface.
You can start to see more visible layers as your layers won’t have enough time to cool down before the next layer is extruded.
What you need to do is follow the following steps:
- Reduce your extruder temperature gradually until you have the optimal printing temperature
- You can implement a temperature tower to test different temperatures with your filament
- Make sure your cooling fans are working properly
- Speed & temperature are closely related, so if your temperature is high, you can also increase the speed
Other Methods to Remove Layer Lines
Post-processing is a great method of removing layer lines from your 3D prints. When you see those seriously smooth 3D print models on YouTube or just around the internet, they are usually smoothed other using various techniques.
Those techniques usually boil down to:
- Sanding Your Prints: This does an amazing job at getting rid of layer lines and just making your parts very smooth. There are many different levels of sanding paper to give you a finer finish. You can also use a wet sanding method for extra shine.
- Covering it Polish: You can polish the 3D print to make it look smooth. One of the most widely used polish sprays is Rustoleum, which you can get from any hardware stores.
Just to bring the article together, the best method to reduce your layer lines is to decrease your layer height and use a smaller nozzle diameter. After that you want to dial in your temperature settings, control your overall temperature settings in the room, and use some high quality filament.
Make sure your 3D printer is well-tuned and maintained so mechanical issues don’t contribute to bad print quality. For that extra push, you can implement post-processing methods to really smooth your prints over.
Once you follow the action points in this article, you should be well on your way to 3D printing without layers.