We now have quite a few online tools to create lithophanes of all kinds, flat, round, even in colour…
Looking at the suggestions those websites provide we can see that we find two flavours.
Printed flat on the bed or printed standing up vertically.
So what’s the difference and benefits ?
If you do the Bambu way with CYMW filaments you of course print flat as otherwise you poop more than what you print.
A rounded lithophane of course has to be printed vertical until we can print in non-planar ways one day…
Resolution and print time matter as much as printability here.
Using a 0.2mm nozzle is said to provide the best results, no matter the orientation.
But it also means the time required to print it usually doubles compared to using a 0.4mm nozzle.
If you check the slicer preview you can see the fundamentally different result without even printing anything…
Flat means you are limited to the layer height and nozzle diameter to get details.
Vertical also relies on the layer height but seems to offer a much better resolution.
Problem is that printed vertical you somehow have to deal with those gaps between the layers…
Arachne certainly helps a lot but still isn’t perfect.
So which one is better ?
I go on a limb here and say it all depends on just two factors:
Whether or not you print in colour and how big the lithophane is.
Of course, if it can’t be printed flat there is no question which orientation is better…
The average thickness for white filaments seems to be from about 2.4 to 4mm.
The finest detail we can print vertically is what the extrusion width allows for, like when printing gears and such.
Since those lithophanes SHOULD not come with any bad overhangs they should come out just fine vertically.
For small to mid sized lithophanes it is often the fastest and most detailed print.
On the other hand, large lithophanes often come out much better printed flat.
No issues with overlapping lines, gap infill or unavoidable gaps.
Means the image appears more defined and more clear.
What’s the best print settings ???
Vertical:
Check the thickness of the model, divide by the wall widths and then again by 2.
This results in all layer printed as just walls.
Depending on the contrast ratios of the image you might still require some gap infill here and there.
Classic wall generator should be checked first in the preview.
Pay attention to possible gaps and areas with lots of overlap.
If it looks fine go ahead, if not compare to how Arachne slices it.
A big factor here is the extrusion width!
The finer the better the details but it comes with the risk of loosing layer adhesion.
Outer and inner walls set to 0.42mm should work fine.
You can try an off-balance approach as well.
Like using 0.6mm for inner walls and 0.42 for other walls.
As said, the goal is to reduce gaps, overlaps and areas where the plastic might build up too much and affect the surface quality.
Layer height is a bit tricky here…
The lower we go the lower our print speed.
Trying a 20cm tall print this way might take a bit of time in 0.08mm layers…
Doing it 0.2mm layers certainly speeds things up but might cause details to get lost.
Thing is that all this can be quite relative based on the image orientation.
The layer lines are ALWAYS horizontal…
If the image is rotated by 90 degrees those lines would be vertical in the printed lithophane, making it much better for a direct view from the front.
Some larger one you might hang in the window could benefit from being printed the other way around so those layer lines won’t interfere too much based on different (side) viewing angles.
0.10mm layers seems to be near perfect for mid sized lithopanes, large one can be done in 0.12 without loosing to much detail.
Keep the preferred viewing distance in mind here 
If you can see those layer lines from the distance you should check the lithophane then they won’t be a problem…
Printed flat…
We could try the wall approach and just print with hundreds of walls for a larger lithophane…
But that would neither be efficient, not kind on our printers.
I have seen a lot of ‘tutorials’ on Youtube claiming to show the best way to print flat lithophanes…
In all fairness, a few got it right but the majority seems to have no clue and produced bogus…
Unlike vertical lithophanes we don’t have to worry much about line gaps and overlaps but we do have to worry a lot about the filament parameters, especially the flow ratio.
We need to print SOLID, means we we have no room for error.
If the previous layer looks bad the next one won’t fix it and we have no sparse infill to start over on the top!
But I just assumed you calibrated things in order to come out clean and smooth before attempting lithophanes…
We of course need a proper first layer.
And we shall use a rather low layer height, like 0.1mm or 0.08mm.
If this first layer does not come out smooth and free of saw tooth profiles around the walls from the infill then calibrate the filament properly please.
We do need many walls loops and should stick with no more than 2 or 3.
For thin layers if your settings and calibration allow for it a single wall works best here.
The reason it that the layer breaks AND the breaks between wall loops affect the light differently than the solid plastic.
With just one wall loop we usually manage to get the infill overlap to result in a clean and smooth transition, both alone the perimeter and OVER the wall loop for the overlap.
How many top and bottom layers you wonder now and what about the infill ?
The infill of course needs to be 100%, which only really leaves the rectilinear infill to select.
Now think for a moment about WHAT we are doing here…
We want a SOLID model with the least amount of flaws, especially when printing in colour…
And since all this is rather complex for the slicer we also want to reduce the actual print time to just the amount required.
The lithophane usually comes with a MINIMUM thickness, like 0.3mm…
Means we have room to play with but we have no need to play…
Do a test print at your preferred layer height and check how many TOP layers you need to create a smooth surface over a solid infill layer.
THAT is how many top layers you need to set, should not be more than 2…
We do NOT need bottom layers as we print solid
Being a lithophane by nature means we only need solid layers but no walls and bottom layers to build up on.
You only ever need a wall where a new layer is higher than the one below - to hold the infill in place.
Let me sum it up:
Thin layer height of 0.1 or 0.08mm
1 or 2 wall loops only
100% rectilinear infill
NO bottom layers
1 or 2 top layers
Classic wall generator should do fine
If you print flat lithophanes like this would will see a quite nice reduction in print time while the model comes out looking much better than using the standards approach with top and bottom layers.
The key to success is to settle on a layer height that works best for you.
If it is too much of a nightmare to get the 0.08mm right than stick with 0.1mm.
In order to get a meaningful result you also need to match your lithophane thickness to the lightsource in question!
For example one hanging on a window not getting any direct sunlight might need to be rather thin while one for a lightframe can be printed much thicker.
In either case you should print some solid test plates to check what the minimum thickness has to be for a good white and how thick it has to be for a dark enough grey.
Let’s apply some physics to this, shall we ?
Let’s say your lithophane has a minimum thickness of 0.3mm and a max thickness of 3.6mm.
Printed in 0.1mm layers this means looking at roughly 32 layers where the brightness levels change.
A simple grey scale test print reveals where or not we get matching levels of black and white like this.
32 different thickness for our row of patches - yes you can use a lithpohane generator to make them…
In most cases you will find that you end up with less than satisfying differences and no real black.
Changing to a different filament can make a big difference, same for using more layers.
Unless you need true black you should be fine…
If you would use a matching lightsource to allow you to print a few more layers you get more levels of grey in the image.
Does that mean though you should aim for the max ?
Physics can be a female dog when it comes to 3D printing…
Our enemy here is called RETRACTIONS.
No worries when printing vertical but a factor to consider when printing flat!
A simple cartoon character that only has 8 or 12 colours in the image is no big deal.
A photo of someone standing in front of a detailed and colourful background a nightmare.
The more of these little islands per layer there are in your print the more retractions you have.
The more details in an image the more islands in the print…
There is a setting in every lithophane maker that applies to the pixel density of the image.
You should be aware how this affects your STL file!
A small value gives you really detailed STL file with a huge file size.
Something in the range of 0.2 or above a quite small file…
For a logo you won’t need too much detail in terms of brightness levels…
But you still need defined edges and for a photo you certainly want to be able to recognise the people in the image…
Half the nozzle diameter is all you need here, so around 0.2 for a 0.4mm nozzle and around 0.1 for a 0.2mm nozzle.
The reason is that the printer can’t do a dot, it has to move the head for a minimum distance in order to provide a good bond and no blobs.
You should do some test prints to find the largest pixel value that still give you enough details, no need to go any lower.
How many different brightness levels can you really get?
In theory as many as your image has…
But with the amount of light being reduced per layer we have limitations.
A translucent filament will allow for far more layers than a solid white one.
The real question would be how much time you have and how much you want to torture your extruder…
I have done lithophanes in 0.05mm layers using a 0.2mm nozzle and in a thickness of just over 4.5mm…
The difference for the same image printed in 0.1mm layers using a 0.4mm nozzle however does not justify the print time.
Yes, for a small lithophane you do want a 0.2mm nozzle but once you reach a certain size you should refer to a 0.4mm nozzle.
the layer lines are a product of a software glitch on the bambu printers (dont appear with the same file on other printers) wear the supports connect to the lotho. I am still trying to figure out why. I suspect there is a bug that that overwrites the settings and irons or over excludes the connector levels.
either way if you remove the supports and print with custom supports that connects the whole way or just a skirt there are no lines. My main concern with the skirt is that its not much support for a tall litho.
I have to say Bambu has really dropped the ball on this line issue. its obviously a software bug and they have left it for months
Hey, here my 50 cents.
I print exclusively 1 color vertically. The default settings are fine except the outer line width which I set to 0.38 in order to get better details.
But still I GET WORSE RESULTS then I get with Cura and my old DIY printer. Bambu Studio slicer somehow rounds all wall edges up and the resulting image is way softer in sight then when printed wit Cura and my old printer. This was a stab in by back because I bought the printer exactly for that purpose. Now I am looking for way how to use Cura slicer with Bambu Printer…