
As for their most important trait, that still lives on , is the multiple haircuts and hairstyles they designed, for example "The pompadure" wich consists on holding the hair back with grease or wax, there's also he ducktail, commonly used with gel nowdays, consisting on forming the hair on the back of the head as a spike or, well, a duck's tail.
There are lots of other variations, like the pompadeur change that travolta wore in "grease" , recognised by the pair of bangs that stuck out.
In the UK, the sister trend of the US "greasers" where the "Rockers"(tough they still exist,they are not called rockers anymore, as that term goes for another subculture nowdays).
The rockers wore a very similar clothing, but their hairstyles were vaguely different, while they too used wax, they aimed for a curlier style, wavier and with more volume, possibly because they used to race in motorcycle, without a helment, so they didn't care that much for their hair, tough they were still called greasers by they're rival gang, the mods, this was because usually after coming off the motorcycle they used to take out a little can of pomade and pass a brush with it trough their hair.
So even if both these subcultures have been in constant decline, when we see someone wearing a leather jacket, we don't see them with a green shirt and an afro, thanks to the greasers we associate leather jacket's with carefull hairstyles, rockabilly music, white shirts with rolled up sleeves, and maybe jhon travolta.
Even today their trend of rolling up cigarettes on their sleeve's is very common, and 3 years ago up until now hair wax has seen a huge revival, V neck shirts are also coming on as top fashion, wich was almost a trademark neck cut for greasers.
So it's a fashion trend that come and goes, but the hairstyle is a constant in our society nowdays.
For extra info, or to greasefy yourself, watch here.
Popularizing the greaser style.
Greasers were originally a style that was representing rebellious attitude that was later adopted as a frontwards stylish fashion style.
the thing that made them mainstream all over the world was the movie grease , wish stars travolta as Danny Zuko, and is a musical rockabilly film in wich a guy falls in love with a woman, but in front of his friends he acted really bad with her.

Towards the end of the movie the moral kicks in: the guy turns out to stop caring about what their friends say, and starts to truly love her.
It was a high grossing film, wich is still nowdays portrayed as "la onda vaselina" in mexico in theaters, "grease" in america and UK and 13 other lenguages.
in that age, the candy shop bars became very famous, a place to drink milkshakes and munch some fries, with black and white floor, sometimes with waitresses in rollerskates.
it was a very fun age to live in.
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