Executive summary

Rating: Selective Accumulate. My base case is that three tiers of 1990s San Marco compound and the rest does not, so the only position worth adding is a platinum 37mm with a famous ship or Hong Kong subject, low number and full set, bought in a European room and sold in Hong Kong.

This is a dated price study of 1990s Ulysse Nardin San Marco cloisonné enamel watches and of the newer UN enamel that shares the same Donzé Cadrans workshop. The question is whether the category appreciates, and whether the workshop link makes UN enamel undervalued against other brands that buy from the same bench.

My conclusion is that appreciation is real but narrow. Three tiers have moved since 2024: platinum 37mm ship and landmark subjects made in five to ten pieces, the 1997 Hong Kong handover series, and the striking San Marcos (Hourstriker, minute repeater and jaquemart pieces). Everything else is flat or below original retail: ordinary yellow gold 25 piece editions without low numbers, the 40mm versions of the 2000s, the Classico enamel of the 2010s, and current Freak enamel bought at retail.

The most important finding is geography. Platinum 37mm San Marcos of comparable rarity sold in Europe for EUR 8,528 to 16,250 between July 2024 and April 2026, while Phillips and Antiquorum Hong Kong took HKD 106,250 to 304,800 for the same tier, a two to four times gap. It is not a brand problem, it is a question of where the buyers are.

On the Donzé underdog thesis, my verdict is that it partly holds. The price gap is real, the craft is real, the mechanism is wrong. The workshop has never sold the premium; the brand name and the enameller's signature do. UN owning Donzé since September 2011 is an option on a future signature, not a valuation today.

Disclaimer: analysis of public auction and dealer data as of 2026-09-04, not investment advice. Liquidity here is extremely thin and every price below is a single observation, not an index.

Price anchors

All results include buyer's premium where the house reports that way. Antiquorum results may not state the premium basis. Configurations are as catalogued.

DateHouseLot / configurationResultRead-across
2026-05-31Antiquorum Hong KongSan Marco Trafalgar 131-77-9, yellow gold 37mm, No. 1/25HKD 187,500Same watch (movement 13.14.12577) made HKD 93,750 at the same venue on 2019-10-27. Low number plus famous ship doubled in seven years
2026-05-09Phillips Geneva XXIIIPatek Philippe 2523 "South America", yellow gold, Stern Frères cloisonné dialCHF 7,961,000 (about USD 10.2m)Category ceiling and reference-level record. Same workshop as the Universal Genève row below
2026-04-26Monaco LegendSan Marco Chillon Castle 139-70-9, platinum 37mm, No. 8/10EUR 16,250 (est. 10,000 to 20,000)European high for a platinum 37mm ten piece subject; still below Hong Kong's 2021 level
2026-06Sotheby's New YorkSan Marco 131-77-9, yellow gold 37mm, No. 2/25, box and papersUSD 16,640US mid-market for a low-number gold example. Sotheby's online Fine Watches, 8 to 17 June 2026, about twice the estimate per aggregator data
2025-12-14Ineichen ZurichSan Marco Golden Hind 136-77-9, yellow gold 37mm, No. 19/25CHF 14,000 hammer, no premiumA dealer then listed a Golden Hind No. 19/25 at EUR 25,000 negotiable (observed 2026-09-04): dealer asks run 70% over hammer
2025-11-21Phillips Hong KongSan Marco "Musée" / Victoria Harbour 139-70-9, platinum 37mm, possibly unique, box and certificatesHKD 304,800 incl. 27% premium (hammer 240,000; est. 100,000 to 200,000)Record for a three-hand San Marco. Hong Kong subject plus platinum plus documents; treat as the exception, not the base
2025-11-21Phillips Hong KongSan Marco Victoria Harbour 136-77-9, yellow gold 37mm, No. 1/28, full setHKD 203,200 (est. 70,000 to 140,000)1.45 times top estimate. Gold also benefits when the subject is local
2025-11-21Phillips Hong KongSan Marco Flying Cloud, platinum 40mm, No. 2/30, unworn full setHKD 127,000An unworn 40mm platinum trades under a used 37mm platinum. Case size counts
2025-11Phillips Hong KongJungle Minute Repeater Jaquemarts 729-20, platinum 39mmHKD 1,778,000UN enamel ceiling. Complication plus enamel plus Hong Kong reaches seven figures in HKD
2025-10Monaco LegendSan Marco Matterhorn 131-77-9, yellow gold 37mm, No. 10/25; Trafalgar No. 20/25 same saleEUR 25,000; EUR 18,750Rare non-ship subject can out-price a famous ship in Europe
2025-05Antiquorum Hong KongSan Marco USS Constitution 131-77-9, yellow gold 37mm, No. 11/25HKD 68,750Ordinary number, sixteen years flat: HKD 72,000 was paid in Hong Kong in 2010
2025-11-21Phillips Hong Kong XXIVacheron Constantin Audubon 43060 (1997, ten per subject): lot 845 Carolina Parrot, Anita Porchet signature; lot 844 Band-tailed PigeonHKD 762,000 vs HKD 457,200Read with care. Phillips catalogues both dials as signed by Anita Porchet, and the three Muriel Séchaud dials in the same session (lots 846 to 848) made HKD 406,400 to 609,600. The 67% gap between the two Porchet dials therefore measures subject, and the Porchet name lifts both above the Séchaud dials
2024-07-13Antiquorum MonacoSan Marco Amerigo Vespucci 139-70-9, platinum 37mmEUR 8,528Platinum alone does not price. Cold subject, European room
2024Phillips GenevaSan Marco Porto Bello 139-10, platinum 40mm, No. 20/30CHF 16,510Against a USD 55,500 archived retail for the 40mm platinum series: about 70% loss from retail
2024-05Christie'sRolex 6100 "Les Armoiries", Stern Frères cloisonnéUSD 304,920Same watch sold for USD 317,000 in December 2015. Nine years, no growth, at the very top of the category
2023Phillips Hong KongSan Marco Hourstriker, platinum, No. 10, champlevé dialHKD 139,700Up from CHF 43,750 for a platinum Hourstriker at Antiquorum in 2010
2021-06-05Phillips Hong KongSan Marco Rialto Venezia, platinum 37mm, No. 10/10HKD 226,800Hong Kong baseline for a platinum ten piece landmark; still above Europe's 2026 high
2020Christie's GenevaUniversal Genève cloisonné rooster dial, circa 1955, Stern FrèresCHF 13,750Same workshop and decade as the Patek 2523. Roughly 500 times apart

Dealer asks for reference only, observed 2026-09-04: platinum 37mm Gorch Fock 1/5 USD 19,631 and Gibraltar 1/5 USD 26,269; platinum 40mm Achille USD 27,090. A private Reddit sale of a Gorch Fock 1/5 full set was cut from USD 14,600 to 13,000 in 2024 and did not sell. Chrono24 had two cloisonné San Marcos listed worldwide.

Thesis

The thesis I was asked to test reads: demand for cloisonné enamel is rising; Donzé Cadrans is one of two or three workshops left in Switzerland that can do it; Ulysse Nardin has owned Donzé since 2011; therefore UN enamel, and especially the 1990s San Marco, is undervalued against other brands using the same craft. Split into four claims:

Claim 1, demand for enamel is rising. Holds, with a caveat. Phillips wrote a dedicated cloisonné essay for Geneva XXIII in May 2026 and the 2523 "South America" made CHF 7,961,000. A Patek 5231J trades above retail (USD 96,273 in July 2026 against USD 81,610 list) and a platinum 5131 made HKD 1,088,000 in April 2026. The caveat is that even the rarest Stern Frères Rolexes show no compounding: the 6100 "Les Armoiries" is down nominally over nine years, the 6102 "Caravelle" is up 2.8% (CHF 1,235,000 in 2015 to CHF 1,270,000 in 2024). What is rising is demand for branded, signed enamel at the top, not for "enamel" as a category.

Claim 2, Donzé is rare and supplies major brands. Rarity holds, the client list only half holds. Eight artisans, five years minimum training, more than 700 colour recipes, a scrap rate reported as high as 75% on grand feu. Brands that publicly confirm Donzé: Ulysse Nardin (owner), Czapek and Louis Erard. Patek Philippe, Hermès and Cartier appear only in press paraphrase ("supplies brands like...") and none has confirmed it. Patek runs its own métiers d'art workshop and names its enamellers. "Donzé also makes Patek" is the emotional fuel of the thesis and should not appear in any post or listing.

Claim 3, UN owns the asset. Legally holds, commercially unrealised. UN bought 100% of Donzé Cadrans SA from Francine and Michel Vermot on 1 September 2011 (FH and SJX, verified). Fifteen years on, Donzé still takes third-party orders, UN prints "Email Grand Feu" on the Classico dial (a technique, not a workshop), has never signed a dial with Donzé or an enameller's name, and did not get a single mention in Phillips' 2026 cloisonné essay. UN treats a two-or-three-left asset as a production line, not as a brand.

Claim 4, therefore UN enamel is undervalued. Does not hold as stated. The gap exists. Whether it is a mispricing is a different question, and history has already run the experiment once. See below.

What the evidence shows

The Stern Frères precedent. In the 1950s Stern Frères made cloisonné dials for Patek Philippe, Rolex, Vacheron Constantin, Omega, Audemars Piguet, Universal Genève and Longines. Seventy years later the Patek 2523 is CHF 7,961,000 (May 2026), the Universal Genève rooster CHF 13,750 (2020) and a Longines Saudi map dial HKD 75,000 (Antiquorum Hong Kong, 2013). Same workshop, same decade, same technique, and the multiple never closed. Sharper still: the Stern family bought Patek Philippe in 1932. The dial workshop owned the brand, and value still attached to the name on the dial. UN buying Donzé is the same structure inverted, with the same result so far.

The Donzé ladder, 2024 to 2025 retail. Louis Erard Le Régulateur Grand Feu Enamel, steel 39mm, 99 pieces, brand confirms Donzé: CHF 4,500. UN Classico Manufacture Grand Feu, steel 40mm, 170 pieces (2016): CHF 8,500. Czapek Quai des Bergues Black Enamel S, steel: CHF 16,000; No. 25 white grand feu, steel: CHF 19,200; No. 33 rose gold: CHF 25,900 to 34,000; Sursum Corda, rose gold, 10 pieces: CHF 36,500. UN Freak S Enamel, titanium 45mm, 50 per colour (2025): CHF 153,000. One supplier, thirty-four times between bottom and top. A single-colour grand feu dial takes eight to fifteen hours; a 1990s pictorial cloisonné was reported in 1993 at about 54 steps, twelve firings and roughly 100 hours. The row with the most craft, a 1990s platinum 37mm cloisonné at EUR 8,528 to 16,250 in Europe, sits in the lower middle. No rung is held up by the word Donzé.

The enameller's name is priced. Vacheron Constantin's 1997 Audubon series was made in tens. At Phillips Hong Kong in November 2025 the two Anita Porchet dials made HKD 762,000 (Carolina Parrot) and HKD 457,200 (Band-tailed Pigeon), while three Muriel Séchaud dials from the same series made HKD 406,400, HKD 444,500 and HKD 609,600. Subject drives the spread inside each name, and the Porchet name lifts the ceiling. Phillips' cloisonné framework names five value drivers: brand, named enameller, subject, rarity and the lustre of old pigments. UN scores on subject and rarity only.

1990s San Marco results by metal. Platinum is not a premium on its own: Amerigo Vespucci in platinum made EUR 8,528 in Monaco in July 2024, and a Gorch Fock 1/5 full set found no private buyer at USD 13,000. Platinum plus a Hong Kong room plus a famous subject is the formula: Rialto 10/10 HKD 226,800 (2021), Musée HKD 304,800 (2025). Yellow gold 25 piece editions split by number: No. 1/25 Trafalgar doubled to HKD 187,500, while an ordinary No. 11/25 USS Constitution made HKD 68,750 in the same city a year earlier. Sixteen years flat for ordinary numbers, doubled for low numbers with full sets.

By subject. The 1997 handover series (yellow gold Victoria Harbour, 28 pieces; platinum skyline, 10; the Musée, possibly unique) carries a structural local premium, from HKD 112,500 for a platinum 8/10 in 2017 to HKD 304,800 in 2025. Chinese subjects (Zheng He, Chung Chun, Dragon, Temple of Heaven) show the same effect: a Temple of Heaven 40mm rose gold No. 2/36 made HKD 212,500 at Antiquorum Hong Kong in May 2026, the only 40mm to clear that level. Cold subjects (Chillon, Vespucci) get discounted wherever they sell.

Set completeness and originality. Full sets and low numbers carried the premium in every venue that showed one. Because Donzé can make a replacement dial that is very hard to distinguish, original-dial proof, service records and an archive extract are the value core.

Auction geography. Antiquorum is the historic UN venue; Phillips Hong Kong began writing San Marco essays in 2021 and set both 2025 records. European rooms (Monaco Legend, Ineichen, Antiquorum Geneva and Monaco, Finarte, Dorotheum) report results in this tier at EUR 7,560 to 25,000. This suggests a regional difference worth examining. Subject, condition, fees, currency and the small number of bidders prevent treating it as a repeatable arbitrage or assigning a timetable for convergence.

Which references benefit, and which do not

ConfigurationEvidenceCall
Platinum 37mm ship and landmark subjects, five or ten pieces per subject, 1992 to about 2000, especially full sets with low numbers and famous shipsIndicative Hong Kong range: HKD 150,000 to 230,000, with the HKD 304,800 Musée as an outlier. Same tier in Europe: EUR 15,000 to 20,000. Confidence medium: some subjects have never sold publiclyAccumulate
The 1997 Hong Kong handover series in either metalThe apparent uptrend depends on one 2025 sale after eight quiet years, so broader evidence is neededAccumulate
Striking San Marcos: Hourstriker 759-20 platinum, Sonnerie en passant 751-22, the 701-22 minute repeater and 729-20 Jungle jaquemartsCHF 43,750 (2010) to HKD 139,700 (2023) for the Hourstriker; EUR 50,000 (Monaco Legend 2024) to HKD 1,778,000 (Phillips Hong Kong 2025) for the repeaters. An Oechslin-era house movement answers the ETA criticismAccumulate
Yellow gold 25 piece editions: numbers 1 to 5, full set, famous shipCutty Sark in gold was a 12 piece edition rather than 25, a special series at the time. Trafalgar No. 1/25 doubled to HKD 187,500 in seven yearsAccumulate
Yellow gold 25 piece editions: ordinary numbers, with papersOrdinary-number USS Constitution HKD 68,750 (2025) against HKD 72,000 (2010); Europe EUR 12,500 to 25,000Hold
Gold and rose gold city, building and cultural subjects (Venezia, Algiers, Matterhorn, Corrida, Pisa, Chung Chun, Zheng He, Dragon)Europe EUR 12,500 to 25,000; Chinese subjects carry a Hong Kong premium, the rest only sell when the subject is wantedHold; Watch the Chinese subjects
40mm cloisonné of about 2003 to 2009 (139-10 platinum, 136-11 rose gold, 30 to 36 pieces)USD 55,500 retail to CHF 16,510 at auction, and the case sits on the wrong side of the small-case revival. Chinese subjects are the exceptionReduce; Watch the Chinese subjects
Classico enamel 2011 to 2022: zodiac champlevé in editions of 88, ship cloisonné in 30Retail CHF 39,800 to 42,900 (Schooner America, 2016), auction CHF 15,000 (HMS Caesar, Antiquorum 2017). A Horse No. 00/88 went from HKD 189,000 (2022) to HKD 114,300 (2023). Same Donzé craft as the 1990s: the cleanest proof that craft alone does not appreciateAvoid at retail
Modern Freak X Enamel (CHF 38,000 to 46,000) and Freak S Enamel (CHF 153,000) at retailThis study has no completed secondary transactions for these configurations. The Classico's retail discount cannot establish a discount for a different modelAvoid at retail
Ordinary-number gold without box and papers, and any restored or replaced dialNo venue has shown a premium for either; a replacement dial collapses valueReduce
Any platinum example offered in a European roomEUR 8,528 to 16,250 for the same tier that makes HKD 106,250 to 304,800 in Hong KongWatch as a buyer; never sell there

The calls follow one rule from the data: the market pays for subject, number, documents and venue, not for the enamel itself. Accumulate covers the three tiers with a visible uptrend, and only in the configuration that showed it, bought in European rooms at EUR 10,000 to 16,000 for platinum, CHF 40,000 to 60,000 for a Hourstriker, EUR 50,000 to 80,000 for a jaquemart repeater, and exited at a Phillips or Antiquorum Hong Kong autumn sale. Hold means the piece is fine to own and not worth adding. Reduce means the tier has flat or falling comparables and I would use a strong Hong Kong season to lighten. Avoid at retail is for anything still on sale new: the Classico shows a 60% retail loss and the Freak enamel has no secondary record yet. Watch marks a sub-group, mostly Chinese subjects, where one or two Hong Kong results suggest a premium that is not yet repeatable.

Risks

  • Enamel condition. Hairline cracks cannot be refired away. A replacement dial is technically possible at Donzé and would collapse value. Inspect the dial first and never restore.
  • Thin category. Two cloisonné San Marcos on Chrono24 worldwide, private sales unsold after six months, dealer asks 30% to 70% above auction. One Hong Kong sale can set or break the trend.
  • No signature yet. The discount to Czapek-level pricing closes only if UN establishes a Donzé or enameller signature and archive language. That decision sits with UN, not with owners or with Donzé. An option with unknown expiry.
  • Brand health. Morgan Stanley estimated UN at about CHF 69m of sales in 2024, ranked 40th, with short-time working at Sowind that year. Another change of ownership or a cut at Donzé would damage the living workshop story.
  • Catalogue errors. References 139-20, 139-70-9, 131-77-9, 136-77-9 and 130-70-9 overlap within the same subjects and houses regularly misstate them. Sotheby's hides results behind login; Antiquorum does not always state the premium basis. Match caseback engravings to certificates before using any comparable.
  • Rarity is not compounding. Rolex 6100 and 6102 show the top of the category going nine years without growth.
  • FX. Four currencies, no conversion applied; the venue gap is partly sensitive to HKD, CHF and EUR moves.
  • Movement. The 37mm three-handers run the UN-13, a chronometer-grade ETA 2892-A2. The value is entirely in the dial.

Horizon view

HorizonViewWhat would change it
Short (0 to 2 years)Hong Kong rooms keep paying for rare subjects: platinum five to ten piece editions and the handover series firm, ordinary gold flat, Classico soft. The Europe to Hong Kong spread of two to four times is the most actionable feature of the market and I expect it to narrow within about two to three years as European houses learn to catalogue San Marco.Further completed sales by subject, metal, condition and venue, including unsold lots, to test whether the Hong Kong premium is repeatable across comparable pieces. A Hong Kong season without a six-figure HKD San Marco result would move the platinum tier to Hold. A European house writing a San Marco essay would close the spread early.
Mid (3 to 5 years)UN's 180th anniversary heritage push, the rediscovery narrative (FHH, 1916 Company, Watch Brothers London, WatchProsite, Chinese-language media) and the small-case revival put 37mm platinum in front of independent-watch collectors; 40mm stays under pressure. The Donzé thesis stays at partly holds.Catalogue research and archive evidence identifying the dial workshop or enameller: it improves attribution but does not by itself establish a premium. Any two of five signals would move my Donzé verdict to holds: a Phillips, Christie's or Sotheby's catalogue naming Donzé Cadrans or Michel Vermot on a San Marco lot; UN archive extracts recording the dial workshop or enameller, or a signed dial on a new UN piece; a San Marco placed in an enamel-themed sale next to Patek and Rolex cloisonné; UN reissuing a 37mm cloisonné San Marco at a high retail (the Daniel Roth and Gerald Genta pattern of 2023 to 2025); sustained Chinese-language coverage and results turning the Phillips Hong Kong premium into a stable local market. Another change of UN ownership or a cut at Donzé would move the whole line down a notch.
Long (5 to 10 years)Brand tier and signature decide the ceiling. Patek cloisonné sits at seven figures, UN at five, and that distance does not close. The rarest single pieces, striking San Marcos and platinum editions grind higher; ordinary 25 piece gold tracks inflation at best; 40mm and Classico stay below original retail.Collector interest in specific subjects, repair options and the continuity of enamel expertise, which set liquidity and ownership costs. The Rolex 6100 and 6102 record shows that even the top of the category can go nine years without growth, so future appreciation is uncertain and a signed-dial policy from UN is the only lever that changes the long view.

Methodology and data

The price data come from two research memos dated 2026-09-04. The first collected 239 price points across eight angles (Asia, auctions, catalogue, dealers, macro, merit, sentiment, strategy) with source URLs, then re-checked the twelve data points most likely to change the conclusion against the original auction pages: seven matched, four had detail corrections (mostly sale date or premium basis; the Phillips Hong Kong November 2025 lots sold on 21 November, not 23) and one was overturned (a Japanese dealer sold label with no evidence of a transaction, excluded here). The second memo tested the Donzé thesis against brand disclosures, retail pricing and the Stern Frères precedent. For this report I verified by web search the Donzé acquisition date (FH and SJX, 1 September 2011), the Patek 2523 South America result (CHF 7,961,000, Phillips Geneva, 9 May 2026) and the Louis Erard and Czapek retail prices. For the rated revision I also opened the Phillips Hong Kong XXI lot pages (844 to 848, 853 and 856), the Antiquorum lot pages for Trafalgar (2019 and 2026), USS Constitution (2025) and Amerigo Vespucci (2024), and the CHF and EUR cross rates for 2026-09-04.

Limits: no platinum Cutty Sark has ever sold publicly, so that configuration is priced only by comparables. Several Sotheby's results sit behind login. Antiquorum premium treatment is not always stated. Attribution of individual 1990s dials to Michel Vermot's Donzé is a reasonable inference, not a per-piece fact. Dealer asks are asks, not prices. Third-party corroboration was only partly completed. I own a watch in the tier this report rates most favourably; read the verdict with that in mind.

Sources