Tough resin-not so tough?


Is anyone using the new tough resin.

My feedback is that it is not tough at all, in fact is softer than the black resin, and waaaaay softer than the regular clear resin. Also it is opaque/green in colour see thru.
We have rinsed in isopropanol and post cured under a nail varnish UV device for 2 hours

All feedback appreciated!! How to make it tough


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Tough resin is tougher (not stronger) than the general purpose resins. It is more impact-resistant and less brittle. As such, it has more creep. You can learn more about its material properties and stress-strain curve here.

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Its more resistant to the brittle fracturing… the tough material is more like ABS which is in turn more flexible with out cracking. The standard materials are harder in material science when things are harder they become brittle. The standard resins are so hard that I compare them to porcelain when in as soon as it cracks it is a complete failure, there is almost zero machine-ability and no flex in the parts.

Tough material provides the step down in hardness and ups the flexibility.

My process for running tough parts is as follows

Remove part from build platform within 2 hrs of completion

Soak and tumble in 99% IPA for two minutes
Soak only in 99% IPA for 20 mins
Shake/Tumble for 2 minutes

Remove from IPA and let air dry for 2-8 hrs depending on part thickness (thicker parts or parts with lots of channels need more time to dry)


My parts have come out great I have even done living hinges with this material for customers.


Thank you for your process, I recently printed my biggest tough part yet (4.5"x2.25"x.75" clamshell) and had a tough time with warping.

Our processes were identical for the IPA wash but I put my part directly into our post cure once dry instead of letting it sit for a few hours. Our post cure heats the part a small amount but I think this is unavoidable unless you want to use a very low wattage UV source for a very long amount of time.

I assumed my problem was from the printing itself as the resin is quite flexible while building and was going to simply try more numerous supports with smaller contact points.

Why do you remove the part within 2 hours and why let it sit between washing and post cure for so long? TIA for your help!

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I allow the drying time to ensure the IPA is completely evaporated off the part before curing. I have noticed that if I do not do this step my parts come out tacky and not fully cured.
The reason I remove it from the build platform that quickly is that I have found that the material does have a tiny amount of a creep involved till it is fully cured so the more it hangs the more the part may distort. It is also just a best practice for me to ensure I do not drip too much back into the resin tank below the resin that may drip maybe contaminated or not cured all the way therefore causing small floating flaked in the resin vat… just helps me know I do not need to filter the resin as often…

Here is a pic of my curing “chamber”

its simple but no heat is involved and I bought two types of power supplies (50w and 30w) so that I can control the power wattage though the LED Strips. 30w is what Formlabs recommended with tough resin which I assume the slower curing helps with the material properties. The faster you cure it the harder and more brittle it becomes.

Thanks for your notes and theories.

RE:Creep - I always assumed the supports which are generated to withstand peel forces would be more than enough to counteract creep. You are right that the effect isn’t negligible. Even if it is an excusable amount it is best practice to not let it sit too long. My experience reflects this actually; First clamshell was finished immediately and had minimal warp, second one was left overnight and resembled a Pringles chip.

RE:Curing Intensity - Interesting that you found a faster cure to create a more brittle part, some users may find this appealing as Tough is quite flexible. Now I’m wishing we had our Tough at the same time as our loaner UV flood at work. I used it to post cure flexible parts and at 950 mW/cm^2 it only took a few seconds. If I have some spare time at work or am bored on a weekend I would love to investigate this relationship further.

I’ll try your improvements on the next iteration of the clamshell housing and report back.

Another concept that people used for the older resins was after the part was air dried from the IPA rinse was to put the part in a glass container filled with water and cure it that way. I was curing the clear resin parts in under 10 mins and they were brittle (the clear clouded a bit when that was done but that should not affect the tough material since its clouded anyways) But I have not tried this method with the tough resin. It might help it might not. I will see if i can run some tests in the next week or so doing underwater curing with tough material.

I have done both. I think it helps but I can never seem to knock all the micro-bubbles off of the surface of the model when doing this, not sure if they have any effect or not. The tough prints I did in air took longer to remove the tacky feel but they were also considerably larger.

Post-cure underwater is the ONLY solution for the flexible resin.

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