Strongest resin?

Some people ask me what the strongest resin is.
I don’t have a clue…

I do have the next resin:

All for the form1+.
Can someone tell me what is the strongest / most unbreakable resin of the resin above?




Hardest / Most brittle is clear, white, and gray
I think that Black is a little lower then those three per my testing, but material specs show that it is the same hardness

The tough resin is strong but slightly flexible it is the closest to ABS plastic you can get from Form Labs

Flexible is extremely weak compared to the rest.

I have never used castable so I cannot speak for the strength on that material.

Realistically, none of those are very durable. The black/grey/clear/white are all very hard/brittle. If you need something that can be man handled a bit, you will need to step up to either the Tough resin, or perhaps MadeSolid’s Vorex.

Tough Resin is definitely our best contender for durable, impact-resistant applications. Check out the specific data sheets that we have for our resin types; note that the clear resin datasheet covers the properties for clear, white, grey, and black.

You might also be interested in a more in-depth explanation of what makes Tough Resin “tough”:

If you have other special performance you’re looking for in a resin, feel free to share a note here as our materials team is constantly improving existing materials and exploring new properties.

I only use black resin anymore. I have had the most successful prints with it. I have noticed that it gets more brittle over time. When parts are new, the do not break if dropped on the floor. Those same parts after 3 or 4 months will shatter when hitting the floor.

put a UV protective clear coat spray on them as soon as you are at the desired hardness and it should hold for a longer period of time. There is UV light in everything and over time it keeps curing the part till it is in my opinion over cured.

I have been making prototypes with the clear resin. It isn’t as brittle as people say and much stronger than the gray or black and not as elastic as the strong resin.
HOWEVER… I prewash the parts in yellow magic and only do a light quick rinse in IPA to remove the tackiness (approx. 30 sec) which gives me a nice smooth surface.

Full IPA cleaning on the clear will make it fragile as it does with the gray and black resins. The colored resins are pigmented clear resin and the pigments serve no structural benefit to the part other than looks.

The casting, flexible and strong resins are different formulations and are have specialized properties.

If your part doesn’t have fine detail and is going to be abused the strong resin should be good for it, Most general printing I have good luck with the clear and find it hold up well in my mold making process and it offers superb detail.


You might want to follow this thread. I’ve been experimenting with the materials and have found a 50% / 50% (by weight) mix of Clear and Tough, heated to ~38C in the tank, and printed on the Black settings produces the best quality and the strongest prints I have ever been able to produce on the Form1+.
Knock on wood, every part I’ve done this way has been absolutely awesome. It’s the only way I print now.


That’s good to know. Maybe Formlabs and refine that combo and make a new resin with the exact exposure for it.

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