Even if you haven't seen American Hustle yet you'll have probably seen snaps of Bradley Cooper's immense 1970s perm.
This week the star - who is rumoured to be on the cusp of popping the question to his girlfriend Suki Waterhouse - told all about his barnet in a Google Hangout with the LA Times.
Turns out the film's hair department decided to manually curl his lid each morning - a process that took three hours! - rather than simply popping a wig on his head.
"We tried a lot of wigs, and I just looked like somebody from Three Stooges. So we curled it.
"They put this solution in it and we put 110 curlers in it and I sat underneath a heat lamp for 45 minutes... The whole thing was three hours.
"I've got to say, man, that I personally kinda fell in love with it. I definitely would try to stave off showering as long as I could because the minute the water touched it, it went limp. But I definitely went out with it at night."
Watch the full interview here...