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Print Quality Issue with Black Resin


I have tested my Form 3, but its print quality is not satisfying… so far…
Perhaps printing parameters of some resin types are not set up well currently.

Shown below is a resolution test model with 0.05mm layer thickness on Form 3.

Shown below is printed with the same layer thickness on Form 2.

As you see, the F3 print seems somewhat over-cured.
Of course, My Form 3 is new, and its optical passes are all clean.

Finally, I gave up using the black resin on Form 3. It seems better to wait for updates.
I am going to try the white resin and hope it can be better.

As you can notice, we cannot get more F3 resin tanks currently. It is pretty annoying to change resin types with only one resin tank.

Form 3 accuracy
Form 3 vs. Form 2 Faceoff!
PoisedWhale reporting for duty
Form 3 Resin Availability: Update

Thanks for the report. Is that model available online so I can try mine too?




This is for only one model.
[ .form file ]

[ .stl file ]


I’ve NEVER had black print that nice on my Form2, even when new and I haven’t tried on the Form3 since tanks are on lock-down and any order for them won’t ship just yet.


Thanks for the files, I’ll give 'em a try in various resins on my Form 3.

Also I ordered 3 Form 3 tanks a couple weeks ago and got them the next week. It says 3mo on the website, but I emailed and asked about it and they said since I already own a Form 3 it won’t be a problem to send them now.


It’s a very interesting test, thank you for this comparison!
I’m waiting for my Form 3 and I become always more worried about this new machine… Almost everybody report issues or lower quality on the form 3 than the form 2. So question @Formlabs , is it only a question of time until the fine tuning on the software will be done on every kind of resin / setting, or problems come from the hardware?


That’s a pretty stark difference in surface quality and achievable wall spacing. I had expected the Form 3 to do better at features like this perpendicular to the build platform, due to the perpendicular laser and optical filter. Please keep us posted with what you hear from support and whether any forthcoming updates/patches improve things.


Here’s my print on the Form 3 w/ .05mm thickness. I don’t have a Form 2 to compare it to myself. I used your .form file so it’s setup just the same way. I think it’s pretty similar to your results on Form 3. The biggest problem to me is the resin pooling up in the gap test. I’d like to do some print-in-place stuff, but seems like I gotta space things out at least .6mm to ensure separation.

It took 3h16m to print (just one).

I hope it’s simply that they don’t have the resin settings dialed in quite yet. If so this could be fixed in a firmware update.

I’ll try more prints at different orientations and with different resins.


One thing that occurs to me is there does seem to be a resonance in the sound the motor is making when printing at various points of operation. Perhaps that vibration is reducing accuracy.


I’ve printed this 3x now at .05mm layer heights. post-processed them for 10m in form wash and 60m in form cure. The left one is the .form file from above which is angled using black (I removed the supports on this one). The middle one is also using black, but printed flat, and the third one is using the original .form file (at an angle).


None of them are that close to the Form 2 example above. I’ve never used a Form 2, and I’m a bit concerned to learn that the Form 3 is producing lesser quality parts. I really hope this can be fixed w/ a software update.


Thanks for sharing. Don’t suppose you have a higher-res image handy of that last shot? Have you tried any other layer heights (e.g. 0.1mm)?


Sure, I had to scale it down to embed, but here it is on Imgur:


Oh, and no I haven’t tried .1 for anything yet. I’ll give it a go w/ grey and post it here. Between grey and black at .5 the results seem similar, but grey is easier to see the details in I think, esp in a photo.


Hey all,

Thanks so much for taking the time to voice your concerns about Black resin!

I can’t offer many specifics at this time, but I can say we’re absolutely aware of these concerns, and we’re working hard on software improvements that will be released as efficiently as possible.

I’d expect there to be significant improvements over the next few months as we are able to implement feedback and data into software/process improvements now that thousands of units are in the field. Please keep the feedback coming! We look at all of it and take it into account.


Thanks for letting us know DKirch. Any details you can offer would be great. Timelines or an explanation of the problem for example.

I printed the tolerance test linked from the FormLabs white paper titled “Engineering Fit: Optimizing Design for Functional 3D Printed Assemblies”.

I can’t insert the test pin in any of the holes. I can get it about halfway into the biggest hole, but it’s very tight.



Have you ever checked galvo mirrors and the main mirror inside of your Form 2?
Especially, you’d better check signs of contamination on the galvo mirrors by fine dust.
A flash light is good for inspecting the mirror surface.
If there is fine dust on the mirror, there must be contamination by the power of the laser beam.

After cleaning all optical passes. my Form 2 was reborn and its print quality got super fine. :wink:
You’d better follow Formlabs instruction for it.

Good luck~




Thanks for printing the same model on yours.
Now, I see I am not alone on this ship… :sunglasses:

Yes, your print seems also over-cured, but a little better than mine.
I have tested other standard resin types.
Unfortunately, all of them are in the almost same quality.
The worst one is with the white resin.

Shown below is printed with 0.05mm layer thickness, white resin on Form 2.

Shown below is with the same layer thickness, white resin on Form 3.

With clear resin on Form 3, and somewhat better.

With grey resin on Form 3.

I tried 0.1mm layer thickness with the grey resin, but worse than 0.05mm.

Please check the Formlabs PreForm release notes. You can find layer thickness setting improvement notes on version 3.1.1, but most of them seem not perfect at this moment as DKirch mentioned.

I had expected better results with the grey resin because Formlabs showed a feather(wing) print sample, but was disappointed by my result.

All prints seem pretty over-cured.
Shown below shows some dimensions of the test model.

However, the results are all pretty chunky.

As you mentioned, we cannot get any kind of clear gaps.
Form 2 print shows clear gaps. (below)

However, the current setting of Form 3 is very serious.

Now, I am totally tired of keeping cleaning my only one resin tank for changing resin types.
At this moment, I give up testing mine.
I believe it seems quite better to wait for the next PreForm update.

Anyone who has not received Form 3 yet, you do not need to envy people already got it.
We are struggling with it.
Also, Formlabs mentioned ‘the next few months’ for its software improvements.

When galvo mirrors or the main mirror of Form 2 is contaminated by fine dust, we usally get a very similar result.
However, Form 3 is new, so I hope that all the issues are due to parameter settings of the software, not due to the LPU or the foggy resin tank film.


PoisedWhale reporting for duty


Yes, I also hope this issue is due to the software, not the hardware.


Thanks for doing all that testing, in your own time, with your own resin!

I have to say once more, I’m not impressed at all with how FormLabs handled the Form 3 release. We are currently only printing Tough resin with our Form 3 and were pretty satisfied by the quality (less so by the speed that is lagging significantly behind the Form 2 at the moment).

Good to know that it isn’t worth it to clean our (for now) only resin tank and use it for Grey, but that we better keep those prints on our Form 2s…



Yes, I also expected better quality.
As you know, the higher the expectation, the greater the disappointment.
I hope it can be solved as soon as possible.

However, another big unexpected difference is the print time.
It is more than 1.5 times longer than by Form 2.
A small and simple model takes similar to using Form 2, but there will be much longer print time for many models or any big model.

My print samples are all tilted.
I will post results with the flat layout.