Star Wars: 10 Things You Didn't Know About Darth Vader's Suit

10. The Mask's Interior Was Made Of Some Very Odd Stuff

Vader's signature mask is the most important part of his costume, with its sunken eyes and creepy mouth-grill making him look intimidating at all times.

But actually designing the thing wasn't easy. In the 1970s - while working on the first film - costume designer John Mollo faced several challenges, including a limited budget, as well as the need to make sure the mask fit actor David Prowse perfectly.

But 2005's Revenge Of The Sith posed a completely different challenge altogether: deciding what the inside of the mask would look like.

Since the interior had never been seen on film before, this was brand-new territory for the entire team. Concept design supervisor Ryan Church spent a lot of time mapping out the look, before handing the actual building task over to special effects artist Don Bies - after George Lucas approved, of course.

And how did Bies bring the inside of the mask to life? A mixture of computer hard drives and collar spikes, amongst other items. Why exactly someone had a spare spiky collar lying around, we'll never know.