I'm new to the whole "40k cosplay armor" thing, but definitely not new to costuming (Mandalorian Mercs, 501st, various Marvel/DC/anime heroes). That said, I've worked in various materials (sintra, aluminum, plastics, steel, cloth, foam), but have never had to source material for a costume as large as a Space Marine. I've built items (and much more often, built items for friends) out of the EVA foam flooring tiles, but never really bothered to source an alternative since I didn't need the larger sizes.
With that in mind, where is the go-to (read: cheapest or best) place to get large sheets of EVA foam?, preferably 12mm thickness.
Thank you ahead of time, and if anyone has any pointers, feel free to go ahead and include them!