Fritz: Dude, we’re out of papers. Floyd: Then go to the quickie mart, Homeslice. Fritz: No, not that kind. I have to send Grandma a thank-you card for that platypus-print sweater. Floyd: Swing by the Upper East Side’s latest addition, LetterHeads. It’s a snazzy stationery shop with brands like Crane & Co., William Arthur, Envelopments, Mia Carta, and Haute. You can find thank-you notes, cards, gift sets, invitations, save-the-dates, and more. Fritz: What if I have a particular design in mind? Like a dragon lighting a doobie with his fire breath? Floyd: Then the in-house graphic designer can custom-make it for you. She also does logos and business cards. Fritz: No way. Floyd: Way. They’ve got killer wrapping paper, too. Fritz: Write on, bro. LetterHeads, 600 Northeast 72nd Terrace (305-751-4894).