The Short Answer

A fake Cartier Tank Must in yellow is judged on four hard specs: case size, dial lacquer, plating thickness, and movement type. The large Tank Must measures 33.7 mm by 25.5 mm. The small measures 29.5 mm by 22 mm. Yellow appears in this line in two forms. The first is the vintage Must de Cartier, a vermeil case with a yellow lacquer dial built from the 1970s through the 1990s. The second is a gold-tone steel Tank Must with a yellow strap or lacquer accent. Decide which one you want before you study seller photos, because the checks differ.

Know the Two Yellow Variants

Vintage Must de Cartier, yellow lacquer dial

Vermeil means sterling silver with heavy gold plating, and Cartier used roughly 20 microns of gold over .925 silver. The dial carried a high gloss lacquer with printed Roman numerals and the Must de Cartier script. Most of these watches ran on quartz. Case sizes sit near 30 mm by 22 mm on the ladies model and near 33 mm by 25 mm on the larger one.

Modern gold-tone Tank Must

The current Tank Must is stainless steel. A gold-tone version is a plating job, not solid gold. Genuine yellow gold Tank models exist at a far higher price, so a seller who calls a plated steel watch "solid 18k" tells you what you need to know.

What You Need Before You Start

  • Digital calipers that read to 0.1 mm
  • A 10x jeweler's loupe
  • A kitchen scale that reads grams
  • Genuine reference photos from at least three angles
  • The exact reference number you are comparing

Inspection Steps

  1. Measure the case width and length with calipers and write the numbers down.
  2. Measure thickness at the center of the caseback, then compare both figures to the reference sheet.
  3. Set the watch flat on the scale and record grams. A vermeil Must de Cartier in the large size carries more mass than a plated steel copy of the same footprint.
  4. Hold the dial under a lamp at a 45 degree angle and look for orange peel texture, dust trapped in the lacquer, or a dull spot near the center hole.
  5. Put the loupe on the VII numeral and find the hidden Cartier lettering worked into the strokes.
  6. Examine the crown cabochon. It should be a faceted blue spinel set flush in the crown, not a plastic bead with visible glue.
  7. Turn the watch over and read the caseback engraving. Look at cut depth, font weight, and whether the reference number matches the case size.
  8. Open the caseback or ask for a movement photo. Confirm quartz or mechanical to match the reference you are chasing.
  9. Measure lug width to the half millimeter and check that the strap sits flush at the case with no gap.
  10. Set the hands to 12 and check alignment against the printed numerals in all four quarters.

Red Flags

  • Listing photos that hide the crown side or the caseback
  • Swiss Made printed at the wrong weight or with uneven spacing
  • Seller who will not send a movement photo
  • Case measurements off by more than 0.5 mm
  • Plating worn to copper or nickel at the lug edges
  • Lacquer that lifts at the dial edge under a loupe

Price Context in the US

Vintage Must de Cartier pieces with yellow dials trade from the low hundreds into the low four figures depending on size, condition, and whether the plating survives. Modern Tank Must quartz watches sit near the low four figures new. Treat any offer far under those bands as a sign of a lower tier build, and any offer at full retail as a sign to walk away.

After the Checks

Keep your measurements, weight, and photos in one folder. When you compare a second unit later, those notes let you spot a drifted case size or a thinner plating batch in seconds instead of minutes.