All latex is pretty basically the same. If you want your casting thicker, you either let it "dwell" in the mold longer, or add many layers to the casting.
Do you have a mold you're working with?
I use a couple different thicknesses of latex when casting mine... clean slush-molding latex to do the outer skin, then a thicker mold making latex mixed with wood-flour to bulk up the inside. I also use burlap layered into the latex to give it regidity where needed, like around the helmet mounting area...
yes, it's very strong. On par with a car tire... lol
& foam latex is weak & tears easily. That's why they go through dozens of suits & prosthetics when doing a movie... Essentialy, foam latex is disposable. It's usualy made for single use items, & has a relatively short shelf life, as it degrades over time. Also, it costs ALOT more than plain latex, & is considerably harder to work with. For the average collector/costumer, it's the worst possible choice.
you can get the wood flour from most latex suppliers. It's specificly made as a latex filler, & is finely ground pine dust. it has the consistency of baking flour, but is stabalized for use in latex... It usualy runs under $10 for a 5 pound bag.
different proccesses, but both work fine. You layer the burlap in like laying fiberglass, inbetween layers of latex. The woodflour you actualy mix into the latex to thicken it, then brush it into your mold... for both you still want to do your first few layers in regular latex to make the surface smooth & defect free...
Also, give each layer plenty of time to dry between each coat, or you'll end up with soft or liquid spots throughout your casting when you try to pull it...
HI Brandon try this a thin lair of latex and use soft poly foam to back fill it, thick latex is to heavy and will crack in time. Foam Latex is grate stuff soft and light I use it on most all of my masks if you use good foam it will last P.S. foam latex is cheap. email me if you need help.