Updated on March 03, 2022
This article is our most comprehensive guide to finding the perfect resin 3D printer settings in an imperfect world.
Getting into resin 3D printing is hard. You have to become familiar with many things before starting your first print. “Where do I start?”, “What settings should I use?”, “What model should I print first?” – these are common questions we hear from new users. You do not have to improvise!
Here’s a comprehensive guide to help you to understand key resin 3D printing settings. After reading this, you’ll be ready to face the rewarding world of 3D printing.
Although there are a lot of good learning resources online, many of them are fragmented and cover small bits of information. With 3D printing, many parameters and environmental factors play their roles at once. Looking at only a few of them rarely helps troubleshoot failed prints quickly. Sometimes, changing the settings without fully understanding how they will impact results feels like shooting with a blindfold. You just hope to randomly hit the target, but all odds are against you.
Therefore, we compiled the most comprehensive guide on resin 3D printing settings, explaining what means what. We used terminology from the most popular slicers: Chitubox, Lychee, Prusa Slicer, and Z-suite. Hopefully, this will allow you to have a broader picture of what you can control and make better decisions when running your prints or troubleshooting failed ones.
The calibration part is your best friend
Whenever you get a new 3D printer, new resin, or just a failed print happens for an unknown reason – print a calibration part. The selection of calibration parts available to download for free is pretty decent these days. However, we always recommend printing our AmeraLabs Town. We believe it is still the most comprehensive test out there. This tiny calibration print helps identify exposure settings and evaluate other factors. For example, it can show if your cleaning procedure is good enough.
A few other calibration parts worth mentioning:
Finding perfect resin 3D printing settings
There are no universal perfect settings. But you can find settings that are best for you for the specific model and application.
AmeraLabs town is a tool to find these resin 3D printing settings. Some people rightfully call this calibration part a “torture test”. That is because almost none of the current 3D printers can print this town 100% as it should be. Thus it shows the limits of your 3D printer and resin with given settings. In other words, it shows what details can be printed and which one you will lose with your chosen settings. Therefore, it helps identify if the balance of printed and failed features is acceptable for your intended application.
The calibration part on the left was printed with shorter 1.2s exposure. We have all vertical and horizontal gaps open. Tiny windows on buildings are all open and well defined. We have four rows of pins and a little bit wobbly antenna tower. The chess pattern is also pretty good; however, it indicates some under-cure as the corners do not meet perfectly.
The town on the right was printed with longer 2.2s exposure. The smallest vertical and horizontal gaps are closed, and windows on the buildings are smaller than intended. However, we ended up with five rows of pins and a straight antenna tower. Moreover, the chess pattern is also perfect.
The 1.2s exposure setting might be great for prints that need sharper negative details and clear surface textures. Also, those that do not have many positive features like standing hair. But these settings might not be that great for bigger, heavier models supported with thin supports.
The 2.2s exposure setting might be good for bigger, heavier parts. Such settings can be used for models that require good positive details and can accept the small loss in negative features. Supports printed with these settings will be pretty strong too.
The results of both of these prints are different. However, those different settings might be perfect for different uses. In other words, you need to find your best resin 3D printing settings for your model, resin, and other conditions. So let’s dive in to discuss how different settings will impact your 3D printing results.
Key 3D printing settings
Also called layer height in some slicers.
What is Layer Thickness?
This is the height of a single layer. You can freely choose this setting.
You will need shorter exposures for thinner layers, but the printer will print more layers overall. So even if a single layer cure time is shorter, the whole printing time will be longer with thinner layers.
The thicker the layer – the shorter your printing time will be. However, you will lose details with thicker layers, and the layer lines will be more visible.
What Layer Thickness should you use?
The most commonly used layer thickness is 50 μm (0.05 mm). The layer lines are not very apparent at this thickness without closer inspection. You can use this layer thickness for miniatures, dental models, prototypes, etc.
For highly intricate parts, jewelry and miniatures, people go with 20–30 μm heights. At this layer height, lines become barely visible to the naked eye. However, your 3D prints will take around 1.5–3 times longer at this layer height compared to the 50 μm height.
For faster printing, bigger mechanical parts, prototypes, some dental applications, people 3D print with 100 μm layers. Layer lines are visible with the naked eye. But it takes much less time to print such models.
Here are a few examples printed with AmeraLabs AMD-3 Grey resin on Anycubic Photon Mono 4K 3D printer.
You can see, that the 100 μm layers have visible lines. However, it could be used for bigger models and quick printing.
At 50 μm, layer lines are less visible. This layer height is great for most models.
Model printed with 20 μm layer thickness has almost no visible layer lines. So it is great for jewelry, highly detailed miniatures, highly accurate dental models and mechanical parts.
Printing with 10 μm layer thickness produces similar results to 20 μm, however it takes a lot of time to print the same model. Usually, it is not worth the time.
To sum up, you can use whatever layer thickness you like. If we dig deeper, there are some tricks to get the best results by using layer heights aligned with Z-axis motor steps. But in most cases, if you stick with 5 μm multiples for layer height, you’ll be fine. We always recommend experimenting with that to see what gives you the best results. Take into consideration the time it takes to complete the print and the quality you get with different layer heights. Finally, have different settings ready for different layer heights. This way, you will quickly take the best resin settings for the model you want to print.
Resin manufacturers tip
Most 3D printing resins are designed to print well with layer heights between 10–100 μm. “High resolution” resins will perform better with layer heights below 50 μm. While some “draft” resins will work better with layer heights of 100–200 μm.
Resins manufacturers think about intended layer height when they design their resins. We adjust light blocking components so that light does not penetrate too deeply into the resin, resulting in light bleed. For example, add too much pigment, and the light will not get deep enough to cure layers to each other. That would result in layers separating. While too little pigment will result in parasitic light bleed, causing models to lose details. Ask your resin manufacturer what layer height is best for your selected resin.
Finally, the quality of 3D prints depends not only on layer height but also on the XY resolution of your 3D printer. This XY resolution is the pixel size of a 3D printer’s LCD screen or DLP projector, or a laser spot size in a laser based 3D printer. Usually, it is between 20 μm and 90 μm. In other words, even if you print with very thin layers, the quality is still limited by the fixed XY resolution of your 3D printer. So consider that when choosing the right layer height.
Also, it is harder to print horizontal “bridges” when 3D printing with very thin 10–30 μm layers. To test what distance you can bridge with your 3D prints, you can print this calibration part: https://www.thingiverse.com/thing:4832552
Normal Layer Exposure Time
Also called exposure time, layer exposure time, layer cure time in some slicers.
What is Exposure?
Exposure time defines how long 3D printer will expose resin to UV light to cure one layer. It is often measured in seconds or milliseconds. This setting is one of the most critical ones defining the quality, sharpness, and success of your 3D print.
If your exposure time is too short, layers won’t stick to each other. Connections between layers will be too weak and may break during printing. This often results in failed supports or layers separating mid-print.
This is called under-exposure.
If the exposure time is just a little too short, the positive features of your models will be thinner and smaller. In contrast, the holes and other negative features will be larger than expected.
This is also called under-exposure.
If the exposure time is just a little too long, positive features will be slightly expanded. In contrast, negative features will get smaller.
This is called over-exposure.
If the exposure time is way too long, your overall model will look bloated, and holes will be filled with cured resin.
This is also called over-exposure.
What Exposure time should you use?
To find the right exposure settings for your resin, you will have to print several calibration parts. Print them with different exposures and decide which exposure time gives you the best results.
Check your resin manufacturer’s website to find recommended settings for your resin and your printer. Those resin 3D printing settings won’t be very accurate, but they are still a good starting point. Print with those recommended settings and then several more calibration parts with 10–20% longer and 10–20% shorter exposure times.
For AmeraLabs resins, we have this list of recommended settings.
Resin manufacturers tip
Do not blindly trust settings recommended by the manufacturers, friends, or folk on Facebook groups. Always test those settings and adjust based on your results.
Exposure time depends on the reactivity of the resin, but also some other factors. For example, room temperature impacts resin curing speed significantly. The warmer resin will cure faster, while the colder ambient temperature will slow down the curing speed. That means that you might need to use longer exposures in winter.
In general, recommended room temperature is around 25°C. If your room temperature gets below 20°C, you may start noticing issues with your 3D prints.
Finally, there is no perfect exposure. You always have to choose the right duration based on what you are trying to print. For example, it’s quite common to 3D print pre-supported miniatures. Sculptors of such miniatures always try to minimize support marks on their models. Thus they use supports with very thin tips of 0.1–0.3 mm. Unfortunately, not every 3D printer and resin can print with such small tips successfully. These often result in models detaching from supports. You can either add additional thicker supports or slightly increase your exposure time to overcome this. Increasing exposure will make supports a bit thicker and stronger, but you might lose some details on your miniature. While adding additional supports will add a few support marks on the model that you will have to sand after support removal. Both solutions are perfectly fine, and it’s up to you to choose which one is better for you.
Burn-in Layer Count and Exposure Time.
Also called bottom exposure time, initial exposure time, base layers exposure in some slicers.
What is Burn-in Layer Exposure Time?
The printer cures a few initial layers with longer exposures for a model to better stick to the build plate. This lays a good foundation upon which the remaining model is then built. The longer the bottom layer exposure – the better the model will stick to the build plate.
What Burn-in Layer Exposure should you use?
Recommended exposure times for burn-in layers vary a lot. However, we recommend making it around 8–12 times longer than your normal layer cure time.
If your normal layer exposure is around 2 s, then the burn-in layer exposure should be around 20–30 s.
If your normal layer exposure is around 7 s, then the burn-in layer exposure should be around 70–80 s.
It is acceptable for big and heavy prints to use 15–20 times longer exposures compared to your normal layer exposure. But we do not recommend that in most cases. Double-check other factors if you need such long exposures (look at resin manufacturers tip).
All in all, you should experiment with this burn-in layer exposure time setting. Start with a longer exposure value and print something. If it is extremely hard to remove the model from the build plate, it may indicate that your exposure is too high. Lower it and try again.
You should probably increase burn-in layer exposure if your model falls off the build plate (and nothing is left on the build plate) or it partly detaches from the build plate.
Resin manufacturers tip
Burn-in layer exposure is a key setting related to model adhesion to the build plate. But it is not the only one. If you start having issues with build plate adhesion, look at other factors as well.
If you can, hollow your prints and add vent holes. Hollowing highly reduces the suction that the printer has to overcome when peeling the model from FEP. Thus, you won’t need the build plate adhesion to be that high.
Some 3D printer manufacturers recommend sanding the build plate slightly with 100–200 grit sanding paper. When doing so, you want to keep your build plate even. So be careful not to make any big divots. Instead, slightly roughen the surface of the build plate.
Build plate adhesion failures could also happen because of the uneven build plate. Sometimes printers come with defective non-flat build plates straight from the factory. There used to be such cases quite often in the past. Though nowadays, the quality of desktop 3D printers is much better. To check if your build plate is flat, you’ll need a metal straight edge ruler and a flashlight. Place a ruler on the build plate and shine with a flashlight at the touching edge. You’ll notice the gaps right away.
There’s a good tutorial made by MatterHackers here: “How To: Perfectly Level Your Resin 3D Printer’s Build Plate.”
Also, models do not stick to the build plate well if it goes out of level. So just relevel your build plate if that happens.
Additionally, when FEP or nFEP (PFA) is too tight, too loose, or too worn out, you may have issues with models being pulled off the build plate.
Finally, we do not recommend lubricants on FEP or other adhesion promoters on the build plate. You don’t need to use them with most resins. These are a waste of money and don’t solve the underlying problems. You are basically treating the symptoms instead of digging deeper and finding the underlying reason why your 3D prints do not stick to the build plate. So before turning to such products, just relevel, increase burn-in layer exposure, check the quality of your FEP, and investigate all other options.
Number of Burn-in layers
Also called number of bottom layers, bottom layer count, number of base layers in some slicers.
What is the Number of Burn-in Layers?
This sets the number of layers that have to be exposed with higher “burn-in layer exposure time.” These first few layers are exposed longer to create a good foundation that sticks very well to the build plate.
How many Burn-in Layers should you use?
It depends on the thickness of the raft that you have on your model. You can read more about rafts here: 3D printing raft in resin 3D printing: what you need to know.
The number of bottom layers with prolonged exposure should be at least 2 layers higher than the number of layers in the raft. This will ensure that the entire raft is well cured and that the first two layers of supports also get cured a little bit. This creates a stronger base for the supports and adheres them very well to the raft.
We recommend using 2–4 layer rafts. Then:
- If you 3D print with 50 μm layers, use 100–200 μm raft, and cure 4–6 bottom layers with longer exposures;
- For 20 μm layers, use 40–80 μm raft, and cure 4–6 bottom layers with longer exposures;
- If you do not use a raft at all and print straight on the build plate, then still use only 2–4 bottom layers. There is no need to cure more.
Resin manufacturers tip
If your model partly delaminates in the middle of your raft, then the number of bottom layers may be off. We have covered this setting extensively in our previous article: Why should you not use default 3D printing raft settings?
Some people recommend increasing the number of bottom layers to increase adhesion to the build plate. That is not true. In fact, in perfect conditions, 1 bottom layer is more than enough to cure the model to the build plate. However, we recommend having 2–6 bottom layers for these reasons:
- It helps to even out the unavoidable build plate misalignments;
- If you print with a raft, then the raft is easier to remove when it is thicker.
Transition Layer Count
Also called faded layers in some slicers.
What is the Transition Layer?
Transition layers are the layers between the bottom and normal layers. If you set the transition layer count to zero, then you will print normal layers with normal layer exposure straight away after printing bottom layers with prolonged exposure. Transition layers allow a gradual transition from bottom to normal layers by gradually lowering exposure time over several transition layers. According to Chitubox, transition layers are meant to increase adhesion between layers.
What Number of Transition Layers should you use?
First of all, not every 3D printer supports this setting. So don’t be surprised if it does not make any difference, even if you set something there in the slicer.
Second, you can perfectly print with 0 transition layers as long as you set the bottom layers right. Therefore, we haven’t found much use for this setting yet. So start with 0 transition layers.
Resin manufacturers tip
Start without any transition layers at first. Consider adding transition layers if you see layers delaminating between your base and normal layers.
What is Lift Height?
Lift height is the distance the build plate moves up between layers to separate the printed model from the FEP.
What Lift Height should you use?
The perfect lift height will be high enough to peel the model from the FEP.
If your FEP is thinner, it will be stretchier. Thus, with 50 μm FEP, you might need a higher lift than with 127 μm FEP. If the FEP is large (as in 10 inch printers or bigger), you might also want to use a higher lift. Moreover, if the FEP is loose, you will also need a higher lift. Finally, the needed lift height might also depend on the resin used and its properties.
Our recommended resin 3D printing settings page recommends using 10 mm lift height for bottom layers and 7 mm for normal layers. This is a conservative recommendation. And it’s more than enough to peel models from the FEP in most circumstances.
Resin manufacturers tip
Experiment with this setting once you get comfortable with resin 3D printing and get consistently good prints. See if you can determine the minimum lift height needed to peel the model off the FEP. By lowering this setting, you can significantly shorten the duration of your 3D printing sessions.
Also called platform lift speed in some slicers.
What is Lift Speed?
Lift speed is the speed at which the build plate raises from the bottom to the top after each layer’s exposure. This speed also defines the speed at which the model is peeled off the FEP.
What Lift Speed should you use?
There are two schools of thought and some controversy regarding this topic. Most manufacturers, including AmeraLabs, recommend using lower lift speeds. This way, your 3D printer will slowly peel the model from FEP without introducing unnecessary stress. This is especially important for inexperienced users as we do not want to add additional factors to an already complicated 3D printing process. We recommend using 40–60 mm/min lift speed for normal layers and 5 mm/min for bottom layers.
However, recently some people started experimenting with higher lift speed and determined that speed above 180 mm/min works as well as slower lift speed. People call this faster lift speed “Vroom” settings. We even know some professionals who successfully use 300 mm/min lift speed. Such fast lift speed significantly reduce 3D printing time, thus is an attractive option to try. However, keep in mind that many cheaper desktop 3D printers are not always built out of high-quality materials. Thus, what works for one may not work as well for another. Also, the supports must be placed very thoughtfully to be able to print with “Vroom” speed. Therefore, the overall feedback from people who tried printing with fast lift speed is mixed.
Resin manufacturers tip
If you are new to 3D printing, start with slower lift speed. Then, feel free to experiment and try faster lift speeds once you are comfortable and consistently get good prints.
Be careful; some slicers measure this setting in mm/s, while others mm/min. So, for example, 1 mm/s would convert to 60 mm/min.
You can now set different lift speeds for different sections of lift sequence in newer slicers. This way, you can slowly peel the model from FEP and then quickly lift the remaining distance. Chitubox calls this option TSMC (Two-Stage Motion Control).
However, you only need to lift the build plate high enough to peel the model from FEP. So when the second lift stage would be useful is not clear.
Finally, some printers have maximum lift speed limit built-in. Unfortunately, these override your slicer’s lift speed settings. Thus, don’t be surprised if the printer is still slow, even if you set 300 mm/min lift speed.
Also called platform lower speed in some slicers.
What is Retract Speed?
Retract speed is the speed at which the build plate lowers down into the VAT.
What Retract Speed should you use?
Use whatever retract speed your 3D printer manufacturer recommends. Usually, it is between 150–400 mm/min. This speed rarely has any impact on the quality of your prints.
Slower retract will make your 3D printing session longer.
Resin manufacturers tip
For very viscous resins, we recommend using a lower retract speed. It will create less turbulence and allow the resin to escape underneath the build plate more easily. However, for most resins, the impact of retracting speed is negligible.
Rest Time After Retract
Also called light-off delay, exposure off time, total off time, rest time before lift, rest time after lift in some slicers.
What is Rest Time After Retract?
There was a mess with terminology regarding rest time after retracting for a long time. Most 3D printers and slicers have this setting, but usually under a different name. Some call it wait-time, some light-off delay, some rest time.
Essentially, this setting allows to add a delay to the exposure after the build plate retracts to its lowest position. Right after the build plate gets to the bottom, it stops, and the system waits for this pre-defined duration. Only after this pause, it turns on the light source and starts the exposition of the new layer. After retracting, this rest time brings more time to fully squeeze resin out of the gap between the model and FEP.
What Rest Time After Retract should you use?
0.5 s to 1 s is generally enough for the resin to stop moving. However, it takes longer for viscous resins to get still, so that you will need longer rest time after retract. While liquid resins will need a shorter rest time.
But you must be careful. Different resin 3D printers treat this setting differently. Some 3D printers require to enter the duration of a complete layer preparation cycle. In Chitubox, it is called Light-off Delay. It looks like this:
While with other 3D printers, you just use pure rest time. In Chitubox, it is called Rest Time After Retract. It looks like this:
Resin manufacturers tip
Since slicers treat rest time after retract setting differently, observe how your 3D printer behaves during printing. Run a so-called “dry run.” Print something without any resin in VAT and check if there’s actually a pause for a second before each layer exposure? If not, then adjust this setting until you find the right one to actually give your printer some rest between end of retraction and new layer exposure. If there is not enough rest time after retract, you might notice an uneven surface called “blooming” on your prints. We have covered that is in this article: https://dev2.ameralabs.com/blog/light-off-delay-blooming/
Anti-aliasing, Grey Level, and Image Blur
What are Anti-aliasing settings?
In general, resin 3D printers have LCD screens that operate with black and white pixels. When the pixel is “black,” it does not allow light to go through, and resin is not cured. However, when the pixel is “white,” the UV light gets through the LCD screen and cure resin above that pixel.
However, Anti-aliasing sets the pixels on the edges of the model to grey color, creating smoother transitions between layers and reducing the pixelation effect.
By using Anti-aliasing, you can get smoother prints, less visible layers, and pixel lines. However, theoretically, you might lose some details on the intricate parts of your model.
You can learn more about anti-aliasing from this great explanation video by Autodesk: Sub-pixel resolution for DLP 3D printing.
What Anti-aliasing settings should you use?
Dennys Wang has found that Anti-aliasing level 0 or 2, grey level 0, and image blur pixel 2 gives the best results. You can see his video here: How To Get Smooth Surface With Print Angle And Antialiasing. He also mentions that the use of Anti-aliasing does not result in loss of details.
Resin manufacturers tip
If you are new to 3D printing – start without anti-aliasing. It will give you a better understanding of what your printer is capable of. Once you get consistently successful prints and want to improve the results, then try anti-aliasing.
Also called LED power, Light PWM, UV Light power.
What is UV power?
Some 3D printers have an option to change the output power of their LEDs. This means that the LEDs can produce more UV light; thus, the resin could cure faster.
What UV Power should you use?
We recommend leaving the default setting that was on the printer when you initially received it.
Resin manufacturers tip
By default, UV power is usually set to 60–100%. You can increase this setting up to 100% in order to print faster with shorter exposures. However, by increasing the UV power, you will shorten the life of your LCD screen. UV light and heat destroy LCD screens, so be careful with this setting.
Remember, it’s always a good idea to consult with the manufacturer of your 3D printer.
Other factors that will impact your prints
As we have mentioned several times in this article, you have to adjust your resin 3D printing settings based on what you want to print. You also have to take into consideration several other factors.
The way you support your 3D prints matters. And based on what supports you have on your model, you might need to adjust your resin 3D printing settings accordingly.
On one hand, you can print with very thick supports, with faster print speeds and shorter exposures. However, thick supports will leave scars on your model that you will have to sand down. On the other hand, you can add very thin supports and print slowly with longer exposures. There will be less support scars, but 3D printing will take longer. On top of that, longer exposures might result in the loss of details on the model.
Do you 3D print pre-supported miniatures? Usually, supports are very thin on these. As a result, you might not have much choice but to increase exposure and print slow or add a few additional supports.
Do you 3D print big heavy models? You might want to use both longer exposures and many thick supports to firmly hold it in place.
Do you 3D print jewelry? The models could be so intricate that you would have to use proper exposure. As well as a few very thin supports and very slow lift speeds.
Do you 3D print dimensionally accurate models? The exposure must be perfect. Supports must be thoughtfully placed to support dimensionally important parts of the model. All other factors must be taken into consideration to maximize success.
Supports used also depend on the resin properties. For example, flexible resins require thicker supports, while hard resins will print well with thinner supports.
Always orient your models so that the cross-section of each layer would be as small as possible. Also, avoid quick transitions between small and large cross-sections.
However, sometimes you just can’t orient the model the way you’d like. For example, there are occasions when you can’t place supports on some sides of the model. For example, you rarely want to place supports on the face of a tabletop gaming miniature. Or sometimes, the model is so big that it just doesn’t fit inside the printer in certain orientations. If you see that your model will have large cross-sections no matter what, switch to more conservative resin 3D printing settings.
In general, the recommended resin temperature is around 25–35°C. If your room temperature gets below 20°C, you may start noticing issues with your 3D prints.
Hollowing and wall thickness
Solid models will stick to FEP more than hollow ones. They will also be heavier. If possible, you should always hollow your models. Use wall thickness of 1–4 mm. We recommend 1 mm for smaller models and more for larger models.
Thinner walls will separate from FEP easier. However, models with thin walls will also break easier.
Lastly, don’t forget to add vent holes when hollowing your models.
Your risk tolerance
Lastly, when you need to print big models which use up a lot of expensive resin, you want to use conservative 3D printing settings. Do whatever you can to lower the risk of failure, even if it takes a bit more time to print. Remember, failure will cost you way more – it will cost time and resin to reprint the whole model.
But if you need to print tiny unimportant personal models, then you can go crazy and try out new settings. Such failures won’t cost much to reprint. You can even print several parts of the same model at once. So, if one fails during the printing, others might succeed.
To sum up, there are no perfect resin 3D printing settings in this imperfect world. The best you can do is find the most optimal settings for the model you want to print on your 3D printer. And you can do that only when thinking about the broader picture: your model, supports, orientation, environmental factors, risk tolerance, etc. Hopefully, this article will help you better understand what factors will influence your prints and in what way. Good luck!
Other articles from AmeraLabs
- Better surfaces with Light-off delay. Blooming phenomenon
- Why is it so important to shake the resin bottle?
- Impressive test print for resin 3D printers together with the guide on how to understand its features
- 6 Key Principles of 3D Printing Supports that Work
- Why should you not use default 3D printing raft settings?
Finally, don’t forget to visit our shop!