The short answer
Prioritize case geometry over dial decoration. On a Ballon Bleu replica the three details that expose a copy fastest are case thickness, the fluted crown guard, and the blue cabochon set into the crown. A 33mm copy that measures close to 10mm thick, with a correctly recessed guard and a cabochon with real depth, will read as convincing across a table. A copy with a flawless dial and a case that sits 2mm tall will not. Before you pay, ask for caliper photos of the case flank, a side profile of the crown assembly, and a flat, straight-on dial shot.
Decoding the 33685 string
Cartier does not publish "33685" as a standalone model reference. In marketplace listings the string usually blends the 3368 reference, which covers the 33mm Ballon Bleu, with a variant or seller code appended to it. Treat it as a pointer to the 33mm steel Ballon Bleu rather than a precise specification. That distinction matters because listing text gets reused across 36mm and 42mm copies, and the size difference changes everything about how the watch wears on a wrist.
Confirm three things in writing before ordering: the case diameter in millimeters, whether the movement is quartz or automatic, and whether the bracelet uses integrated end links cut for this case or a generic adapter. A seller who cannot answer all three is not a seller you want handling a return.
Case, crown, and cabochon
The Ballon Bleu is defined by its crown treatment, so spend your inspection time there. The fluted guard curves around the crown and holds it slightly proud of the case, and the blue cabochon sits inside that guard rather than on top of a conventional crown.
- Thickness: the genuine 33mm sits at roughly 10mm. Anything past 11mm will look like a swollen case and will not slide under a cuff.
- Crown guard: the fluting should be crisp and evenly spaced, and the guard should merge into the case without a visible seam or gap.
- Cabochon: blue spinel on the original. Glass or acrylic on cheap copies reads flat and purple under indoor light. Look for a domed stone with a visible highlight and a clean bezel setting.
- Crystal: sapphire with a slight dome. Tap test is unreliable, but a crystal that flexes under a fingernail is mineral or plastic.
- Caseback: engraving should be lasered, not stamped, with clean letterforms and consistent depth.
Dial and hands
- Roman numerals should be printed or applied with sharp edges and even spacing. Blurry numerals are the second most common tell after thickness.
- On many Ballon Bleu dials the word CARTIER is worked into the VII numeral. Check magnification, placement, and letter spacing.
- Hands should be sword shaped, correctly sized, and reach the minute track. Painted blue hands look purple and flat. Blued steel changes tone with the light.
- Sunray or opaline finishes must shift smoothly across the dial with no banding or orange peel texture.
Movement and caseback
Most 33mm replicas run quartz, usually a Swiss or Japanese caliber, and that is a legitimate choice for a small dress watch: thin, low maintenance, and reliable. Automatic versions typically use a Miyota or Seiko derivative or a clone of a thin Swiss caliber. Ask which one, then check whether the rotor spins freely and whether the crown screws down without grit. Hand winding an automatic copy gently is a quick check for roughness in the keyless works.
Bracelet and fit
The bracelet is where a good case gets undone. Polished center links should line up with the case lugs, the clasp should close with a firm click, and the end links should sit flush without daylight gaps. Ask for the link count and whether spare links are included. A 33mm watch on a loose bracelet slides around the wrist and looks borrowed.
What changes across quality tiers
- Entry tier: correct overall silhouette, mineral crystal, painted hands, cabochon glued rather than set, folded or thin bracelet.
- Mid tier: sapphire crystal, blued-style hands, set cabochon, solid links, decent dial printing, quartz or basic automatic.
- Upper tier: near-correct case thickness, sharp fluting on the guard, clean engraving, refined dial texture, reliable automatic with a properly finished rotor.
Pitfalls to avoid
- Buying from photos taken with the watch angled away from the camera. Side profiles hide thickness.
- Accepting a listing that shows one size in the photos and another in the text.
- Assuming water resistance. Treat any replica as splash resistant at most and do not swim with it.
- Skipping the cabochon check. It is the single most photographed detail on this model.
- Paying before the seller confirms a return window in writing.
FAQ
Is 33685 the same watch as the 33mm Ballon Bleu?
Almost always, yes, but verify the diameter in the listing. The same string gets reused on larger cases.
Will a replica pass as genuine?
At arm's length, a well built copy can. In hand, thickness and the crown guard give it away. Buy for your own enjoyment, not for authentication.
Quartz or automatic?
Quartz suits the 33mm case: thinner, more accurate, cheaper to service. Choose automatic only if you accept a thicker case and higher upkeep.
Does the cabochon fall off?
On glued copies it can. Ask whether the stone is bezel set, and avoid knocking the crown against door frames.
What wrist size suits 33mm?
Up to roughly 7 inches it wears well as a dress watch. Larger wrists should look at the 36mm version instead.