Chris Hemsworth & Co didn't wash their costumes for entire shoot of '12 Strong'!

Chris Hemsworth and Michael Shannon have returned with a war drama titled 12 Strong. It's a story of the US Special Forces team called Green Berets deployed in Afghanistan after the events of 9/11. The movie is adapted from the best-selling book Horse Soldiers.

Hemsworth and the crew went to great lengths to make the movie seem more real. Not washing their uniforms was one such extreme.

Dan Lester, the head of the Costume Department, said, "We had an aging department, but in general, you just never wash the clothes and they work so much better because they’ve actually lived in them. We also had the actors wear their uniforms through boot camp to get them used to the weight of them and get that natural wear.

"As the mission in the movie proceeded, the costumes would consistently gather more and more dust and stain which made it look more genuine."

Lester engaged in extensive research on the uniforms worn by the Green Berets in 2001. He also revealed how he had an ex-Special Officer in his team, which aided them to dig out in-depth material about Special Force uniforms and how within few weeks of research the entire team, had a depiction of basic uniform for the force.

Directed by Nicolai Fuglsig, 12 Strong is set to release on January 19.