What is the most brittle resin?

In my research i need to print a brittle stucture so i am wondering which resin is the most brittle.Is it the high temperature resin?

In my experience yes - High Temp is the most brittle. I have not used casting or the dental resins, so I can’t comment on those but I doubt they are as brittle.

If you want to go less expensive go for a standard resin and over-cure it with UV.

All resin be it 3D printed liquid/filament, or cast resin is brittle. We’ve done tests on this. Solid parts handle it best except if the weight too much. Fine pieces will shatter if dropped on a hard surface.

I manufacture a lot of small parts in both 3D and cast resin. I’ve also had customers write to say they broke those parts with heavy handling or dropping on hard floors.

The most relevant spec for brittleness is going to be the impact strength. Looking at the Formlabs star chart, High Temp has the lowest impact strength, so I would go with that. It also has a lower strength than Standard and Rigid, and lower elongation than those two. So based on all of that, yes High Temp is definitely the most brittle. That being said, Standard resins are pretty brittle themselves.

Fully concur with that. I would also use or at least test with standard resins, since they are already pretty brittle and much cheaper / easier to work with so if they work for your application it’s an all win situation.