Bubbles causing rough surface on print

Any body else experiencing bubbles forming forming on their prints? I’m assuming it’s due to cavitation caused during the peel process, even though my models generally have an air gap to prevent formation of vacuum. Bubbles tend to appear on the side of the print furthest from the hinge of the tank. Whilst it isn’t a HUGE problem, it could become one as I start to print models that require smooth surface detail and cannot be sanded (skin wrinkles, cloth folds, etc…).

Thoughts or opinions welcome.


I am using the Monger mixed resin here but I have had the same issue with the normal grey as well.

Do you have any photos you can share with us, Jason? It’d be interesting to take a look. We don’t have a lot of info, of course, on Monger’s resin, but it’d be interesting to see.

Hi Sam

I have attached two images on one side smooth, on the other rough, there is also a (not in focus - sorry) image of the bubbles in the tank

Actually, those pictures don’t really show the problem - I’ll take some more later and post again.


I may have had a similar effect, although I wouldn’t necessarily call them bubbles. Feel free to compare to the picture below.

This picture (amongst others) was enough for Formlabs to ask me to send FurtiveSquid back for repair. Unfortunately, I’m now still waiting for a replacement to be shipped back :frowning:


That does look quite similar - do you get that effect on all sides of the print or just the side opposite the hinge?

Hi Jason,

I’ve had the same happen to me using the Grey resin, so it’s not because of the mix. This is most likely because of the peel mechanism. I don’t think it’s caused by bubbles, because then it would be voids and holes instead of just a rough texture on one side of the print. Also, this mostly happens with large prints. Maybe Formlabs can investigate further and let us know what could be causing the problems. I don’t print large objects too often, so it’s not a huge issue for me, but it has happened before. Here are some bad pictures I took a while ago using my camera phone, but you can see it is similar to yours.

I have one theory, why it’s happening, but haven’t been able to test it. It may be because of pigment settling and clumping up. When you leave the grey resin in the tank for a week, you can see how the pigment settles and clumps up. This could be happening during long prints, or if the resin has not been mixed well before the print. The clumping and the concentration of the pigment will obviously cause under-curing of some of the parts of the print (this explains why it happens on one side only, and it’s usually the side close to the tank). So this results in a very rough looking surface quality.

If you have resin sitting in the tank for more than a few days, I recommend pouring it into a cup, scraping the bottom and getting all you can out of the tank. Mixing it really well in the cup, then pouring it back into the tank. Add a little fresh resin from the bottle (also make sure to shake the bottle well), then using the spatula to gently scrape the PDMS for a minute or so in all directions. Doing this should give you better results.


the side with the roughness is opposite the hinge. On the hinge side itself is some roughness as well, but not nearly as bad as on the peeling side. In fact, this was a cylinder I printed as a test, and the bottom of it was printed so bad, there were holes in it (again, at the peeling side).


It looks like we are all having similar issues. The resin had been in the tank for around a week but I did swirl it around thoroughly (with new resin) in the tank, but this happens pretty much with any print that I do, irrespective of how long resin is in the tank.

I have taken some new images:

Having looked at the screen grab from the form software I was mistaken in my initial claim of the roughness in relation to the hinge section - it isn’t ‘opposite’ but directly facing, whereas when I can actually see bubbling on the surface of the resin it is on the side of the model facing the back and non-hinge side of the tank.


Can I ask, what setting your are printing at?

I noticed that some models, even if they are large may need to be printed at least on the 50 micron setting and even 25 sometimes. What’s happening here may also be a support issue. I’m not talking about the support structures, but layer per layer support. If you print one layer and the cure is not deep enough to support the next layer, you may get this roughness.

You should try printing a smaller version of the batman on the 25 micron setting to see what happens. You can also better position the model, to make sure all the layers are properly positioned for optimum support.


I was printing at .05 with a 60/40 Grey to Cherry Mix. I have now tried to print the attached file - the biggest I have tried - with 3 failures - the middle of which killed my tank by taking chunks of rubber with the hardened resin that was attached to it. The final failure clearly shows thick layers which I assume are caused by stress during the peel process. I am now going to try a small (pants again) model with Spot-GP (Form1 Beta) white and if that works try the big model again. I know the model has integrity issues but I have printed from various angles after running the repair in Preform and the failure seems to be down to the resin not peeling not the model itself - not sure if my shell is too thick (probably) or my air holes are too small (possibly). It’s such a high detail/poly model I’m finding it really hard to to work on my machine with it.

On a related but separate issue - what is this gunk on the inner walls of the Tank? Common sense tells me its the rubber, so should it be there? If so why is it peeling after one use?





That stuff is the PDMS that thinly coated the sides of the tank. I got that on my tanks too. I just slowly scrape them off and remove them.

Printing large things can be challenging on the form1 that’s for sure. I used to think hollowing the model helps, but even that introduces a new problem with the void areas needing internal supports and those failing, etc. Have you tried splitting the model down the middle and printing it that way? I know it’s not ideal, but it’s better than so many failed prints.


Just had to cancel a failed print using Spotamaterials  SPOT-GP (White) Beta mix. Results suck so bad I am creating a separate post.