Inside Korea's Zombie Factory

CELL Technical Art Studios built the rotting flesh and body suits behind Train to Busan and Netflix's Kingdom, and founder Hwang Hyo-Kyun walks through two decades of practical effects work now being squeezed by CGI. The film includes gory prop footage, so it carries its own viewer discretion warning up front.

Why it's free: Free on Great Big Story's own channel; GBS produced and posted it there itself.