20 Mind-Blowing Facts You Didn't Know About Zodiac (2007)

In another case of Fincher's intense attention to detail, the director required an edit that nobody could have predicted.

When cast as a cartoonist or a writer, you would imagine the actor would have some amount of talent in at least one of those fields. Apparently, this wasn't the case for Jake Gyllenhaal, despite his character being both. To film the close-up shots of Graysmith drawing, or handwriting letters, the production brought in a 'stunt' double.

It's not something out of the ordinary for Hollywood, but not many directors would spend time and money digitally retouching the double's hand for extra authenticity. But this is David Fincher we are talking about here, so of course that's something he had to do.

Addressing the decision, the director remarks in the DVD commentary, "Jake's hands are very hairless and pretty". He goes on to state that the double they used had much hairier hands than the actor and retouching was necessary " so Jake wouldn't feel like we'd done him a disservice".