Mad Men is a terrific show for lots of reasons, and it’s rightly been praised for its obsessive re-creation of the fashions, values, and emotional landscape of the early 1960s, a transitional period between the dull, ordered Eisenhower years and the cultural chaos that would soon follow. Part of the fun of watching Mad Men is knowing that we’re watching the tail end of an era—and knowing that few of the characters have any idea what’s about to happen. The show occasionally hints at the deepening cracks in the American order of things, and I’m convinced this will be a bigger and bigger aspect of Mad Men in the episodes and seasons to come.

The show’s fixation on the seemingly superficial details of a bygone era could have overwhelmed a series with second-rate writing or a weak cast. In the hands of less talented people, it might have been nothing more than That Show With the Amazing Production Design. Instead, everything is of a piece: The art direction is so immersive that there are no clangy wrong notes to distract you from the rich psychological world the characters inhabit.

Until the show ends, that is. When the last frame flickers off the screen and the credits start to roll, careful observers—okay, just the font freaks—will notice a curious thing: The end credits are set not in the iconic sans serif used in the opening-credits sequence, and not in, say, Helvetica, which was designed in 1957 and became popular soon thereafter, but in Arial, the controversial Helvetica knockoff that Monotype cobbled together in the late 1980s to avoid paying license fees on Helvetica. The main giveaways are the “R”s and the “G”s:

Thanks mainly to Microsoft, which has bundled Arial with every version of Windows since version 3.1, this “shameless impostor” has become one of the most widely used fonts in the world, if not the most widely used. No respectable designer would ever choose to use Arial, except in small sizes on the web, where its ubiquity must be catered to. The use of Arial indicates that Mad Men’s designers, so fussy about everything else, don’t consider the closing credits to be worthy of their oversight. (You’ll also notice that the single and double quotes in the screenshot above are straight, not curly—another indication that the design staff is not involved. And jeez, I just noticed that the “r” in “Dr. Oliver” is inadvertently non-italic.)

Of course this raises a conceptual issue: Do a show’s closing credits take place outside the world of the show? If so—and it ain’t hard to make that argument—then who cares if the credits are set in a shitty font? Well, then, why are opening credits usually so carefully art directed? They usually don’t exist within the world of the show either. It’s partly because an effective opening credits sequence helps set a tone and a style. So why not sustain the tone and the style all the way to the end of the closing credits?

No one would argue that Mad Men’s producers should spend as much time or money on the closing credits as they did on the opening credits. And it’s not like they necessarily had to choose a font that existed by 1962. (The font in the opening credits looks like Trade Gothic Condensed or a similar classic gothic, but it may well be a modern cut.) My point is, it wouldn’t be hard to choose Helvetica or Futura or even EF Windsor Light Condensed from the drop-down font list in whatever program is used to create the closing credits.

This is obviously a small detail. But Mad Men is a show that matches small details as well as any series that’s ever been on the air. Why does such a pitch-perfect show end with such a jarring anachronism?

Related articles: “The Scourge of Arial” and “How to Spot Arial.”