"Frank" is a difficult movie to describe. Even the best explanations get caught up on one detail: Michael Fassbender wears a papier-mâché head for most of the film.

Yes, the title character of the fantastic indie flick covers his face with a much larger paper one, but that's not really the point of the movie. And the prop is only one aspect of Fassbender's incredible performance. Frank is a complicated character, and making him relatable, human, and emotionally powerful is one of the great acting feats of 2014.

When I spoke with Fassbender and his co-star, Domhnall Gleeson, he described the physical issues that come with wearing the head.

"Definitely can't see not that much at all, very peripheral vision. I can see nothing in front," he said. "For me, the hardest part with the head is singing inside the head and working on an accent and putting the head on. It's like speaking in a box because that's essentially what it is. The reverb inside there took a bit of getting used to."

But apart from the vision issues, Fassbender said that he enjoyed the experience and even expressed the wish to wear it more often. "I want to use the head in all my other performances," he said.

So what would that look like in "X-Men"? Fassbender gave me a hint.

"Frank" opens in theaters on August 15.