Here’s build-notes from a stellar fan-costume for Big Daddy from the game Bioshock:
Starting with the blueprints printed at full scale (HUGE) I made cross sections out of insulation foam and glued them into place. The empty areas between sections were filled with cardboard. This formed what I called the “skeleton” of the body.
The empty cavities in the skeleton were then filled in with expanding foam.
After drying, the foam was carved into the shape of the main body.
After this was completed (and the foam given more drying time so it would retain its shape) the entire form was covered in stretch fabric. This smoothed out a lot of the lumpiness of the foam.
(via Wonderland)