It is usually a very dense polyurethane foam, sometimes by itself ... Most professional model shops will use it. The one big flaw of tooling board is its price — this stuff is expensive.
Foam boards, known for their versatility and practicality, now come in eco-friendly options that cater to both businesses and creative individuals.
No matter what scale you're modeling in or what era you prefer ... Construction adhesive doesn't attack extruded foam ...
It must be tempting for the set department to fall back on the “get a bunch of stuff and paint it silver” model, which can make for a tedious experience for the technically savvy in the audience.