LOS ANGELES, California (CNN) -- Subtlety may not be in Kevin Smith's vocabulary, but a lot of off-color words are. They're sprinkled liberally throughout the writer-director's new movie, "Zack and Miri Make a Porno."

Kevin Smith can't understand why the word "porno" is still a hot button for some people.

The comedy stars Seth Rogen and Elizabeth Banks as roommates and longtime friends who decide that the solution to their money problems is to make a porn film.

Strong language is nothing new for Smith, whose first film, "Clerks," put him on the map with its merrily scatological musings. Though the film had little violence or exposed skin, it was initially given an NC-17 rating by the MPAA based on the language.

"Zack and Miri" was also a possibility for an NC-17, considered the kiss of death by studios because of distributing and marketing challenges, until Smith argued its merits to the ratings board and received an R.

Since "Clerks," Smith's films have been almost wistfully romantic ("Chasing Amy," "Jersey Girl") or as joyfully profane as "Clerks" ("Dogma," "Clerks II"). "Zack and Miri," which opens Friday, is a blend of the two Smiths: full of sex and colorful language, but with a sweet side.

Indeed, Banks told CNN not to be fooled by the film's tawdry talk.

"Kevin Smith is a huge romantic," she said. "He likes to wrap up the romance in profanity, but the guy is more sweet than spicy." Watch why "Zack and Miri" is so controversial »

In an interview with CNN, Smith, 38, cheerfully acknowledged that this is not a film for prudes. The following is an edited version of the conversation.

Kevin Smith: There's a bit of language in this picture. I'm not going to lie to you. ... I don't even think of it as salty. To me, it's just like part of a lexicon.

CNN: Well, you do hear it a lot.

Smith: Yeah, yeah, yeah, no doubt. We're raising our kid in a household where people curse, as an experiment. And I think our experiment is working, because I don't tame my language around the kid. I don't run up to her and yell [expletive] in her face, but I don't go out of my way to like not curse in front of her. And honestly, ironically, she doesn't curse. And I've tried to get her to curse for like friends and family, because it's always entertaining to hear a child curse, and she doesn't do it.

CNN: Well ... I almost hesitate to ask, but tell me what the genesis was of the film.

Smith: It's a movie I've been researching since I was like 12 years old, to be honest with you. And sometimes three or four times a day. ... But it only really came together when I saw Seth Rogen in "40-Year-Old Virgin" and instantly fell in love with him and was like, "I got to work with this guy." ...

So I started thinking about this movie, and immediately it kind of crystallized. Seeing Seth and thinking about porn, I was like, boom, "Zack and Miri Make a Porno." I wrote the script with him in mind. And by the time I finished with it, "Knocked Up" was about to open, and the word was it was going to be huge, so I was like, we missed our window. This guy's going to be famous, and he'll want nothing to do with this movie.

But I sent him an e-mail anyway where I said, "Look, man, I wrote this flick with you in mind. Please give it a read." ... And I got an e-mail back within five minutes that said, "When I first came to Los Angeles, an agent asked me what I wanted to do with my career. I said I wanted to be in a Kevin Smith movie. That has not changed. Please send me the script; I would be honored to read it."

And I was, I was like cha-ching! You know, my God, it worked out.

CNN: You're working with some professionals here, and by that I don't mean Seth and Elizabeth. I mean working with actual people with porn experience.

Smith: We got ourselves a former pro. ... Traci Lords, man. Who, for the last 20 years, has not made an adult film. Has been keeping that industry at arm's length as she concentrates on a mainstream career and her musical career and stuff like that. But you know, it just seemed like if we're going to make this movie, Traci Lords would just fit into it so well.

We approached her agent, and her agent was like, I don't know, it's got "porno" in the title, she ain't going to want to do it. Then she heard that Seth was in it, and she heard that I was making it, and so she was like, well, I'll at least read it. She came over to my house and read it.

And I remember, I was sitting downstairs while she was upstairs reading it, and I was like, if I could go back in time and tell the 16-year-old version of me that Traci Lords is going to be hanging out in your living room ... my 16-year-old head would explode. First, the 16-year-old would be like, where'd you get a time machine, and then the 16-year-old would be like, does she want to have sex with us, and then I'd have to break it to the 16-year-old that, no, Traci Lords -- even many years from now -- [is] still not interested in your fat ass.

So, she loved the material. ... Maybe it's time to embrace it and make fun of it. I said yeah, please do it.

Katie Morgan is still active in the adult film industry, and she brought a kind of a current vision to it. She was able to kind of tell me where to put the camera to make things look as convincing as possible. So I was like, wow, man, this chick who most people know from porn has taught me how to direct. So if the movie looks any better than my normal stuff, it's probably because of Katie Morgan. iReport.com: Will you see 'Zach and Miri'?

CNN: The title has created some challenges in terms of the marketing, that some newspapers are not taking ads for it and some buses and what have you. What do you make of that?

Smith: I think it's strange that in this day and age, the 21st century, that people are hung up on a word, and the word is "porno." It's not like we put salacious posters out there. ... The poster is literally stick figures. ...

People are afraid like, what if my kid asks what porno is? Just tell them. Tell your kid that the porno's not for you. My kid asked me what a porno is, I'm going to be like, guess what? Hannah Montana is not in it. Not yet. Are you still interested? Of course she's not interested in it, because it has nothing to do with her world.

So I just think its kind of sad that like some people lobby against it. Like, based on the dude who called in, or the many people that called in after the Dodgers ran a spot. ... Just tell your kid, man; just be honest with them. It's like, look, [the] movie's not for you. ...

It's crazy to me, because it's like, some people think that it's real porn that's being advertised. Can you tell me the last porno that you saw that had the word "porno" in the title? Like, it doesn't exist. I don't think it's ever existed.

CNN: I understand that you were able to convince the MPAA to give you an R rating. Did that require any cuts? And if not, were you surprised?

Smith: Initially, I was kind of surprised that they gave us the NC-17. Especially because the two areas they focused on were easily addressed: one ... they felt [was] gratuitous thrusting in the first porno sequence between Katie Morgan and Jason Mewes, and the other was what we'll call the egregious bodily fluid shot. ...

I was able to go to the appeals process with the film, where you show it to a different audience. ... [You] screen it for [theater owners], and then you get up and do 15 minutes on why you feel it should be an R. Joan Graves [of] the MPAA gets up and does 15 minutes on why she feels it's an NC-17, then you get 10 minutes to rebut, she gets 10 minutes to rebut. You leave the room, and that audience makes the vote. ... You have to win by a two-thirds majority [to have the rating changed].

And they changed the rating. [The] appeals group that we screened for ... flipped it, gave us an R. And I didn't have to make a single cut, so everything I wanted in the movie is in the movie. That's kind of cool as a filmmaker.

CNN: Your own presidential debate.

Smith: A little bit. ... It was kind of like "Inherit the Wind," but about porn, not the Scopes Monkey Trial.

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