10 Things You Somehow Missed In Zodiac (2007)
2. Wait, That's A Fat Suit?
When an actor has to portray a physically larger character, it's custom to wear a fatsuit. This sort of padding has been used for countless films including The Nutty Professor, Shallow Hal, and the Austin Powers franchise.
But no matter how convincing these bodysuits are, you can nearly always tell it's not legit. Whether it's because the chin doesn't line up or the gut is too bulbous, there's usually some detail that gives it away.
However, next to no one could tell Dermot Mulroney wore padding in Zodiac to make his character, Captain Marty Lee, look more doughy. Normally, fatsuits are used to make a person look dramatically heavier (at least 100lbs). Rarely would a filmmaker feel obligated to have an actor wear padding to look 10 or 20lbs bigger.
Of course, when your film is being directed by a perfectionist like David Fincher, every minute detail has to be exact. So, when he met Mulroney, he felt the actor was too athletic to play a desk jockey. As a result, he encouraged Mulroney to wear padding that left his physical features less defined.