Kim Kardashian's nude cover was "retouched" Us Weekly exclusively learned -- get all the details Credit: Jean-Paul Goude/Paper

Kim Kardashian's famous backside had a bit of help when it came to her now famous nude Paper magazine cover, the mag's editorial director Mickey "Mr. Mickey" Boardman tells Us Weekly.

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"Every cover of every magazine is airbrushed on some level," Boardman tells Us. "But what I will say, is that is her butt. It is not padded. It is not augmented. That is all really her. But, yes, there was retouching to clean things up and make things look amazing," he admitted. "That’s what retouching is. It’s not building an ass that isn’t there or taking 50 pounds off the waist."

Boardman said that Kardashian's famous backside was simply "oiled up" and that photographer Jean-Paul Goude "is a genius with lighting." (A source tells Us that Kardashian's longtime trusted makeup artist Mario Dedivanovic had the honors of "rubbing the oil all over her.")

As far as initial talks about the risque shoot went, Boardman tells Us that they hadn't originally planned for the reality star to drop trou. "There was some ass-related thing that was proposed but we weren’t sure what was going to happen," Boardman explained. "We were really just planning on recreating the [famous] champagne shot…but she came in and was like, 'Let’s, you know, let’s just go there!' She and Jean-Paul just got into it with each other and got excited. She’s not shy about taking her clothes off, and the next thing [we knew], magic was happening."

Boardman, who has worked with Kanye West's wife in the past, complimented Kardashian and gushed she "was amazing" and "is definitely the nicest, easiest celebrity I’ve ever worked with by far."

Photographer Jean-Paul couldn't have been more ecstatic to work with the 34-year-old as well. "He was like a kid in a candy store by the time we got rolling," Boardman said. "He was so happy and so excited with the pictures."