The Forgotten Cartier: Revisiting the Must 21 — Cartier’s Experimental Elegance

In the world of vintage Cartier, a few names dominate the conversation: the Tank, the Santos, maybe the occasional Panthère or Ballon Bleu. But lurking just beneath the radar is a model that’s equal parts 80s boldness, quiet sophistication, and vintage charm: the Cartier Must 21.

We recently picked up a 35mm Cartier Must 21 Quartz in stainless steel and gold — and it's time this underrated gem got the spotlight it deserves.

A Must-Have for a New Generation

Let’s rewind to the late 1970s. Cartier had just reinvented itself.

After decades of producing exclusively high-end pieces in precious metals, the maison realized it needed to adapt to a changing market. Under the leadership of Robert Hocq and Alain-Dominique Perrin, Cartier launched a daring new concept: Les Must de Cartier — “the things one must have.”

These were not the traditional solid gold icons of the past. Instead, Cartier began crafting pieces in vermeil, steel, and gold plate. Think colorful enamel dials, bold designs, and—yes—quartz movements. It was luxury reimagined for the style-conscious, upwardly mobile generation of the 1980s.

The Must de Cartier Tank came first, but by the mid-80s, Cartier wanted something sportier. Enter the Must 21, launched in 1986.

The Design That Broke the Mold

When you first see a Must 21, it doesn’t look like any other Cartier.

Where the Tank is rectangular and the Santos is square, the Must 21 is round, almost coin-like in shape. The bezel dominates the design, engraved with oversized Roman numerals in gold — not on the dial, but on the steel bezel itself. It’s loud, clean, and elegant all at once.

The dial, in contrast, is pared down to the essentials: no markers, no complications beyond a discreet date window at 6 o’clock, and a humble “must de Cartier” script just under 12.

There’s something bold about how little the dial tries to say. It’s confident in its quietness.

Other signature details remain, of course: blued sword hands, a sapphire crystal, and the unmistakable blue cabochon crown — a detail that tells you, even without the name on the dial, you’re looking at a Cartier.

Our specific piece came with a vivid red leather strap (non-original), which adds a punch of color and makes the gold accents pop. Originally, the Must 21 was offered on a two-tone bracelet — steel with gold-plated center ridges, perfectly integrated with the case.

Under the Hood: Quartz Power, Swiss Precision

The Cartier Must 21 is powered by a Swiss quartz movement, often based on ETA calibers but finished in-house by Cartier. In an age where quartz was still considered cutting-edge, this was a practical choice — especially for the younger, fashion-forward clientele the Must line was aimed at.

Collectors often frown on quartz, but let’s be honest: there’s something satisfying about a vintage Cartier that keeps perfect time, never needs winding, and still carries serious design chops. The Must 21 wasn’t made for the purists. It was made for those who wanted Cartier style without Cartier maintenance.

The caseback is screwed down and typically stamped with “must de Cartier 21,” “Swiss Made,” and a unique serial number. Water resistance was modest (around 30m), but for a dress/sport hybrid from the 80s, that was more than enough.

Why the 21? A Name with Mystery

One of the more curious aspects of the Must 21 is its name. What does the “21” even stand for?

There’s no definitive answer, but several theories float around:

• Some say it refers to 21 Rue de la Paix, Cartier’s famous boutique address in Paris.

• Others believe it symbolizes a new generation — 21 as the age of adulthood, a “coming-of-age” collection for the brand.

• Or maybe it was just a stylish number. After all, this was the 80s.

Whatever the reason, the number stuck. And it became the basis for the later Must 21 Chronoscaph line in the early 2000s — bulkier, sportier, and definitely more “Y2K” than the sleek original.

A Quiet Classic on the Secondary Market

Now here’s the fun part for collectors: the Must 21 is still shockingly affordable.

While a Tank Française or Santos Galbée from the same period will set you back thousands, a well-kept Must 21 quartz model can be had for anywhere between €400 and €1,000, depending on condition and completeness.

We picked ours up on Ricardo.ch — a Swiss auction site — for just CHF 402. That’s less than most Swatches cost these days.

Granted, it didn’t come with the original bracelet or papers. But the case was clean, the dial was sharp, and the movement ran perfectly. Slap on a cool leather strap and you've got a Cartier that punches well above its price point.

On marketplaces like Chrono24, Must 21s typically list for CHF 800–1,500, especially if they have the original bracelet. So if you can live without a box or branded clasp, the deals are out there.

Wearing It Today: Still Relevant, Still Unique

In a world that’s rediscovering smaller watches and vintage flair, the Cartier Must 21 fits right in.

The 35mm case might seem small on paper, but with its wide bezel and slim profile, it wears larger than you’d think. It works on almost any wrist, and the clean dial means it plays well with everything from suits to streetwear.

More importantly, it doesn’t look like anything else.

While every fashion influencer seems to have a Tank or a Santos these days, the Must 21 still feels a little secret — a little weird, a little wonderful. It’s unmistakably Cartier, but just unfamiliar enough to start conversations.

Verdict: A Cult Classic in the Making

The Cartier Must 21 might not be Cartier’s most famous watch. It’s not the most collectible, the most complicated, or the most hyped.

But that’s exactly why we love it.

It’s bold, it’s different, and it captures a moment in Cartier’s history when the brand was trying something new — bringing elegance to a wider audience, and doing it with real style.

For anyone looking to dip into vintage Cartier without dropping thousands, the Must 21 offers something truly rare: an authentic Cartier experience, with character and history, at a price that still feels like a steal.

So here’s to the underdogs, the offbeat icons, and the watches that didn’t follow the script. The Cartier Must 21 might have been made for a different time — but it still feels right at home on the wrist today.

Video Review on Youtube