Authenticating a vintage S.T. Dupont is not difficult once you know where to look — but almost every tell is small, and most of them live on the underside of the lighter. This guide walks through them in order, with photographs of genuine and fake examples side by side.
The short version: fakes are given away by their engraving. S.T. Dupont hand-stamps its serial numbers, and a hand-stamped number never comes out perfectly even. Counterfeiters use machines, and machines are too tidy.
Five red flags to check first
Before examining anything closely, these five things should slow you down. None is proof on its own, but each raises the odds considerably:
- A brand-new-looking lighter at a low price. The most reliable warning sign there is.
- Limited editions, extravagant or uncommon designs. These are faked far more often than plain models.
- An evenly spaced, machine-engraved serial number. Genuine numbers are stamped by hand and sit unevenly.
- Muddy, thickly engraved letters and symbols. Genuine engraving is fine and sharp.
- No coloured paint dot in the filler cap. Explained in detail below.
Step 1 — identify the model
You cannot authenticate a lighter until you know what it is meant to be, because the tells differ by line. Turn the lighter over — the underside identifies it immediately.
| Model | How to recognise it | Fake risk |
|---|---|---|
| Ligne 1 | A single screw knob on the base, hiding the gas intake | Low |
| Ligne 2 | Two knobs — one for the gas intake, one to adjust flame height | High |
| Ligne D | Much smaller than the others at 32 x 9 x 54 mm; two knobs | Low |
| Gatsby | Slimmer body; part of the Ligne 2 family, not a line of its own | Low |
Ligne 1 and older Ligne 2 models are faked far less often than modern Ligne 2 pieces. If you are looking at a plain, honestly worn Ligne 1, the odds are already strongly in your favour.
Authenticating a Ligne 1
Ligne 1 models have been faked only in very limited numbers, and most examples you meet are genuine. Age and honest wear are themselves reassuring — counterfeiters make new-looking lighters, not convincingly worn ones.
There are exceptions, and they are worth knowing.
Serial numbers
If a Ligne 1 looks brand new and carries an unusual design, check the serial number first.
A genuine serial number is hand-stamped: small, fine, and unevenly spaced. Some characters sit slightly off the line, and occasionally only part of a symbol has struck properly. A fake serial number is thickly machine-engraved and evenly spaced.
In the photograph above, the first serial number is too large, too muddy and too evenly spaced. The genuine number below it is finer and unevenly spaced, and you can see that it has been stamped rather than laser engraved.
Older genuine Ligne 1 lighters from the 1950s to the 1990s use a larger font. These serial numbers usually do not begin with a 1.
Some fakes are very convincing indeed. On the example above, the letters and numbers are unevenly spaced — so spacing alone is not enough. Judge the quality of the strike as well as its regularity.
Unusual and extravagant designs
A Ligne 1 with an extravagant or unique design deserves more scrutiny than a plain one. Plain finishes were made in enormous numbers and are rarely worth faking; unusual ones carry a premium, which is exactly why they attract counterfeiters.
Laque de Chine
Fake Ligne 1 Laque de Chine models have noticeably larger gold-plated borders around the lacquered surface than genuine ones.
If you want to understand what the genuine lacquer work involves — and why it is so hard to imitate — our guide to the art of Laque de Chine covers the process in detail. You can also compare against the Laque de Chine lighters we have handled.
The red dot in the filler cap
Genuine Ligne 1 lighters run on red gas, and because of this they carry a dot of red paint inside the filler cap. Fakes do not have it.
This is one of the quickest checks available, and one counterfeiters consistently miss.
Authenticating a Ligne 2
The Ligne 2 has two knobs on the base — one for gas, one to adjust flame height. It is by a wide margin the most commonly faked S.T. Dupont, so it deserves the closest attention.
The five checks
Five things separate a genuine Ligne 2 from a fake:
| Warning sign | What a genuine lighter does instead |
|---|---|
| A new lighter at a low price | New lighters sell at high prices through reputable vendors |
| Limited editions and extravagant designs | Genuine limited editions are genuinely rare to come by |
| Muddy or incorrect engraving on the flame adjuster screw | The engraving is sharp and precise |
| A laser-engraved, evenly spaced serial number | The serial number is hand-stamped and unevenly spaced |
| No paint dot in the filler cap | A dot of paint is present in the filler cap |
The arrow and cross
The two most telling marks sit on the underside. A genuine S.T. Dupont has a clearly engraved arrow and cross; on a fake they are muddy and thick. On a genuine lighter the arrow is also not filled in.
This is the single most useful Ligne 2 check, because it is difficult to reproduce cheaply and counterfeiters rarely get it right.
Serial numbers
As with the Ligne 1, genuine Ligne 2 serial numbers are hand-stamped and unevenly spaced. The characters are finely struck and can be genuinely hard to read on a lighter with some wear — faintness is not a warning sign in itself.
The filler cap dot
Genuine Ligne 2 lighters have a dot of paint under the filler cap that conceals the gas refill nozzle. On a Ligne 2 this dot is yellow or green — not red, as on the Ligne 1. Fakes have no dot at all.
Gold and silver marks
If the lighter is presented as solid gold or silver, the marks answer that question separately from the authenticity question.
- A micron figure such as "20 microns" means the lighter is plated, not solid. The number states the thickness of the gold layer. A 20 micron plating is a generous, high-quality finish — but it is plating over brass.
- Solid gold carries the French eagle’s head assay punch (tête d’aigle), which guarantees 18 carat gold, alongside a 750 or 18K fineness mark. Solid gold pieces never carry a micron marking, because there is no plating to measure.
- Weight settles it. Gold is roughly two and a half times denser than brass, so a solid gold example feels like a different object entirely.
For photographs of the marks on real examples, see our illustrated reference of solid gold S.T. Dupont models.
When an unusual lighter is not a fake
Not every lighter that looks wrong is counterfeit, and it is worth knowing the difference before walking away from something good.
- After-market jackets. Independent workshops — Italian ones in particular — produced custom silver and gold sleeves for genuine Dupont lighters. The mechanism is authentic; only the outer skin is third-party. These are not fakes, but they are not factory work either, and the market values them differently.
- Replaced service parts. A lighter serviced over fifty years may carry a replacement flint wheel or valve. That is maintenance, not deception.
- Retailer marks. Some genuine lighters carry a second name — Cartier or Tiffany & Co., for instance — because they were sold through those houses. This adds provenance rather than casting doubt on it.
Where fakes come from
Be careful where you buy. Marketplace platforms such as Etsy are notorious for counterfeit lighters, and any deal that looks too good to be true generally is — a practically new lighter at a very low price above all.
You can always check the official S.T. Dupont website for current retail prices on new models. Vintage and new old stock prices vary with condition and rarity; our value guide explains what actually drives them.
At Avenue of Aesthetic Lighters every piece is checked, serviced and guaranteed authentic before it is listed. You can browse what is currently available, or by model — Ligne 1, Ligne 2, Ligne D and Gatsby.
If you think yours is fake
Work through it in this order:
- Photograph the underside in good, indirect light — serial number, arrow and cross, and the knobs.
- Open the filler cap and look for the paint dot: red on a Ligne 1, yellow or green on a Ligne 2.
- Compare the serial number against the photographs above. Ask whether it was stamped or engraved.
- Weigh it if precious metal is claimed, and look for assay marks.
- If you bought recently, contact the seller. Most platforms have a window for counterfeit claims, and acting quickly matters.
If your lighter is genuine but not running properly, that is a service matter rather than an authenticity one — our guide on caring for a vintage S.T. Dupont covers gas, flints and storage.
Frequently asked questions
Do all genuine S.T. Dupont lighters have a serial number?
Genuine lighters carry a hand-stamped serial number, but on a well-worn example it can be very faint and hard to read. Faintness is not itself a warning sign — a number that is crisp, thick and perfectly evenly spaced is far more concerning than one you can barely make out.
What colour should the dot in the filler cap be?
Red on a Ligne 1, which runs on red gas. Yellow or green on a Ligne 2. Fakes typically have no paint dot at all.
Which S.T. Dupont models are faked most often?
Modern Ligne 2 lighters, especially limited editions and extravagant designs. Ligne 1 models, older Ligne 2s, the Ligne D and the Gatsby are faked far less frequently.
Does wear mean a lighter is genuine?
Not on its own, but it helps. Counterfeiters produce new-looking lighters, so honest age and wear on a plain Ligne 1 is a reassuring sign rather than a defect.
Is a lighter with a silver or gold jacket a fake?
Not necessarily. Independent workshops made custom precious-metal sleeves for genuine Dupont lighters. The mechanism is authentic, but the jacket is not factory work, and it should be priced accordingly.
Can a fake be repaired or serviced?
Generally not economically. Counterfeit lighters use different internal components, and parts are neither interchangeable with genuine ones nor supported by S.T. Dupont.
Ask us to check yours
If you have worked through this guide and are still not certain, tell us what you are looking at. We handle these lighters daily and are glad to give an opinion, whether or not the piece came from us — and we will say so plainly if we think a lighter is not right.
Photographs are what settle it. Send the message below and we will reply by email, so you can attach pictures to your reply. Two shots answer most questions on their own: the underside of the lighter, and the open filler cap.