The Office's Jenna Fischer is usually a pretty sensible person, but all that goes out the door when it comes to her upcoming wedding to screenwriter Lee Kirk. "I thought I was going to be one of those easy-going brides," Fischer, 35, tells Bonnie Hunt in an interview to air Thursday. "I never really thought about it. Whatever … a piece of paper, words – send it out." But that attitude disappeared at the store where she bought the invitations. "Three hours I sat there with the all the books," she says. "I turned into a crazy person. My fiancé was like, 'What about the slap it on the piece of paper with crayon and send it out?' But now I'm pouring over the paper quality!" Guests need to appreciate the invitations when they get them, she says. "Don't just throw it on the counter! Touch it, feel it, love it!" she commanded. But not many people will be seeing the results of her sudden wedding-prep obsession: The wedding will be "very small ... sort of immediate family and friends," she says. "Are you a brother, sister, mother or a father? That's it."