Unfortunately the only way is either from reviews of the final product or if the manufacturer tells you some information about their resin. It seems like most people want to keep it close to vest like some sort of major secret, I can't think of any way of knowing ahead of time :( You could always ask and see what they say!
Smooth cast 300 and 305 is fast great detail resin from one of the largest chemical providers in the US, but it does tend to shatter on impact. That is one of the most common used resins out there. They also make 66D that we use. It was designed by them specifically for the table top gaming community. It comes with a nice mate grey color out of the barrel, the others come white and you can add black pigments to make your own grey. But instead of a quick 10 minute cure cycle it has a 1 hour cure profile. So you have to cycle lots of molds to get the same number of final pieces vs 300 or 305, but the end result is night and day different. It cuts with a hobby knife so smooth and clean where 305 you tend to have to fight a bit and it can chip.
My suggestion would be to ask.
I Can tell you that Bombshell Babes uses the same 66D that we do.