Shipwreck Porcelain: From the Nanking Cargo to Today's Sales

A plate comes out of a cardboard box wrapped in newspaper, and before it is free of the paper you can see that something has happened to it. The glaze is there, blue and white and intact, but it has lost its gloss in patches, as though a fine dust were trapped under the surface. Around the foot rim a band of grey-brown accretion resists washing, and in the well a faint ring of iron staining follows an old crack. Turn it over and the base is chalky, with three small scars where something was cemented to it.

That is what a shipwreck piece looks like. This guide walks you through what the term covers, the Geldermalsen and the sale that created the market for salvaged Chinese porcelain, why the cargoes were blue-and-white, what seawater does to a glaze, the four tests worth running before you buy, and where the paperwork stands.

What the term covers

Shipwreck porcelain is Chinese porcelain that spent time on the seabed inside a hull, and the phrase is used loosely enough to be almost useless on its own. Three different things get sold under it.

The first is cargo material: a wreck with a documented identity, a date, and a quantity of surviving pieces, recovered in a single operation and sold in lots. The Nanking Cargo is the model, and most of what you see offered as shipwreck porcelain belongs to this category or claims to.

The second is chance recovery: a few pieces raised by fishermen or divers, with no site report and no way to date the loss.

The third is porcelain that has merely been in the sea, or in a river, or buried in wet ground, and has the staining to prove it. This is where the trouble starts, because salt damage and acid cleaning can be manufactured on land. How Chinese porcelain is judged for condition covers the vocabulary you need before you accept any of these labels.

The Geldermalsen and the cargo that named a market

The ship was a Dutch East India Company vessel, the Geldermalsen, homeward bound with tea, porcelain and gold when it struck a reef in the South China Sea in January 1752. It lay there until the 1980s, when a salvage operation working the area located the wreck and recovered its cargo, including tens of thousands of pieces of Chinese porcelain.

The porcelain was sold at Christie's in Amsterdam in 1986 and marketed as the Nanking Cargo. The name is a dealer's label rather than a fact about the voyage: the company's China trade ran through Canton, and the pieces were loaded there. What made the sale consequential was not the quality of the porcelain, which is honest merchant ware, but the documentation. Here was a group of objects with a ship, a date, a cargo manifest and a single auction, and that combination gave buyers something the trade had rarely offered: a fixed point.

Two things followed. Prices for ordinary eighteenth-century blue-and-white were reset by the volume, and a generation of collectors learned to date export porcelain by comparing it with a known 1752 consignment. The wreck also taught the trade how to sell salvage: catalogue it as history, sell it in quantity, and let the story do the work.

Why the cargo was blue-and-white

Almost everything on these ships is blue-and-white, and the reason is commercial rather than aesthetic. The company's buyers in Canton ordered to pattern, in tens of thousands of pieces, from Jingdezhen kilns working through the port. The decoration was specified: borders, panels, floral sprays, and a repertoire of designs the European market had already accepted. Under those conditions the safest product was underglaze blue, which was cheap, fireproof in the kiln, and legible on a table at a distance.

The wares are also, by imperial standards, provincial. Bodies are thicker, potting is quicker, the blue is often greyish where the cobalt was economised, and the painting is executed at speed by hands that painted the same spray hundreds of times a day. That is not a defect in the object; it is the object's identity.

For the marks and the dating conventions on this material, Chinese export porcelain marks is the practical reference. The base of a cargo plate is usually where the dating evidence sits: a reign mark written quickly, an artemisia leaf, or nothing at all.

The wrecks that set the reference points

Four other recoveries do most of the work of anchoring the market.

The Belitung wreck, a ninth-century dhow lost off Indonesia and recovered in 1998, carried Tang stoneware and early blue-and-white that changed the chronology of the medium. Its cargo went to a museum in Singapore, which is why you rarely see material from it offered.

The Tek Sing, a Chinese junk lost in 1822 in the same waters as the Geldermalsen, was located in 1999 and produced a cargo of blue-and-white on a scale that took years to absorb. The sale was held in Stuttgart in 2000, and the volume depressed prices for ordinary nineteenth-century export ware for years afterwards.

The Vung Tau and Hoi An recoveries off Vietnam produced Vietnamese and Chinese material from the seventeenth and fifteenth centuries, and both fed the market through large auction sales. Closer to home, the Song-era hull raised in Chinese waters in 2007 represents the other end of the spectrum: a state excavation, published slowly, with nothing sold.

The lesson for a buyer is that a wreck name is a dating tool, not a quality mark. Knowing which wreck a piece came from tells you when it was made and roughly what it is; it tells you nothing about whether this particular plate is worth the asking price.

What seawater does to a glaze

Two hundred and fifty years of salt water is an aggressive environment, and the damage is legible once you know the sequence.

The first change is to the surface. Glaze is a glass, and glass in an alkaline marine environment leaches. The result is a faint dullness, sometimes a patchy iridescence, occasionally a fine craquelure that was not in the original firing. Hold the piece at a low angle to a window: a wreck piece scatters light where a land-stored piece reflects it.

The second is contamination. Chlorides penetrate the body through unglazed areas, especially the foot, and stay there. Iron in the surrounding sediment migrates into cracks and reads as brown staining that follows the break rather than the decoration. Concretion, the cement-like growth of shell and sand, adheres to rough surfaces and leaves scars when removed.

The third is structural. Pieces that were broken on the seabed and later rejoined have edges that have been smoothed by water movement, so the break is rounded rather than sharp. A break with crisp edges on a piece sold as a wreck recovery is a break that happened after recovery, and it is worth asking when.

Glaze bubbles and wear as dating evidence explains how to read the surface under magnification, which is where most of these judgements are actually made.

Four tests before you buy

• The ring. Tap the rim with a fingernail. A sound vessel rings; a cracked one thuds. On a rejoined piece the note changes as you move around the rim, and you can often find the repair by ear before you find it by eye.
• The foot. Look at the unglazed base under a raking light. Concretion scars, a chalky surface and a slightly grey body are consistent with marine burial. A base that has been ground smooth and clean has been worked on.
• The break edges. Water-rounded edges mean the break is old. Crisp edges with a colour difference across them mean a recent break, or a join made from two different pieces.
• The surface under a loupe. Salt bloom sits in the glaze as a faint white haze; acid cleaning leaves a etched, uniformly matte surface with the glaze thickness reduced at the high points. The second is irreversible and it is the commonest damage on the market.

Restoration, and the wreck as an alibi

The salvage label is convenient for anyone hiding a repair. Marine damage is variable, so a plausible wreck piece can carry a filled chip, a rejoined rim or a replaced section, and the buyer excuses all of it as the sea's work.

Work through it in order. Under ultraviolet light, adhesive and filler fluoresce, and a join shows as a bright seam even when the retouching is good. Look at the rim in silhouette against a window: a filled chip is usually a fraction flatter than the original curve. Turn the piece and watch the glaze across the repair; the retouched area almost never matches the sheen of the original, because it is paint over filler rather than glass over body.

Aesthetic repair of a display piece is normal and should be priced in. Restoration that turns a fragment into a whole plate is a different matter, and should be described as such in writing.

Law and paperwork

The legal position depends on where the wreck lies and when it was recovered, and it is not something a dealer's certificate can settle.

International practice is governed by the 2001 UNESCO convention on underwater cultural heritage, which most market countries have not ratified and which therefore shapes norms more than it binds transactions. Coastal states increasingly claim wrecks in their waters, and recovery without a permit is treated as looting. For Chinese material there is a second layer: the rules on exporting cultural relics, which govern what may leave the country and under what category. Chinese art export rules sets out how the categories work.

What this means in practice is that the paperwork you want is the recovery documentation: the site report, the lot label, the auction catalogue from the salvage sale, and any subsequent invoice chain. A one-page certificate of authenticity issued by the seller is not provenance, and on this material it is worth less than the paper it is printed on.

What the market pays, and why volume matters

Shipwreck porcelain sits at the affordable end of Chinese ceramics, and the reason is supply. The Nanking Cargo alone put tens of thousands of pieces into the market in a single week, and later recoveries added more. Scarcity is not doing any work here, so prices are set by condition, by form and by decoration.

Within that, the hierarchy is consistent. Complete plates and serving dishes in clean condition with good blue are the most liquid. Teacups, saucers and small bowls are common and cheap. Pieces with heavy salt damage, acid-etched glaze or obvious restoration trade at a steep discount and are hard to resell.

The honest framing is that you are buying a dated, documented, modest object with a good story. That is a reasonable thing to collect. It is not a store of value, and the market has had four decades to prove it.

Common questions

Is Nanking Cargo porcelain valuable?

Less than the story suggests. The cargo was large, the porcelain is merchant-grade, and the market has absorbed it for nearly forty years. Clean plates and dishes with strong blue hold modest value; common cups and saucers and anything with heavy marine damage are inexpensive. Value comes from condition and form, not from the wreck name.

How can you tell shipwreck porcelain from ordinary antique porcelain?

Look for the combination of a dulled, slightly iridescent glaze, iron staining that follows cracks, concretion scars on the foot, and water-rounded break edges on any repair. None of these alone is conclusive, and all of them can be imitated. The authentication checklist is the sequence to run through.

Does salt damage get worse after purchase?

Yes, if the chlorides were never removed. Properly desalinated pieces are stable in a normal interior. Pieces that were rinsed rather than soaked can bloom again in humid conditions, and the glaze can continue to lift at the rim. Keep them dry, avoid sudden humidity swings, and do not wash them.

Why is most shipwreck porcelain blue-and-white?

Because it was made for export in quantity to a fixed pattern. Underglaze blue was cheap, survived firing reliably and read clearly at a distance, which suited a trade built on repeat orders of tens of thousands of pieces from Jingdezhen through Canton. The blue-and-white guide covers the technique and its history.

Further reading

• Canton export porcelain and the rose medallion palette — the nineteenth-century trade that followed the era of these cargoes.
• How to care for Chinese porcelain — storage, humidity and why desalination matters.
• How to read an auction condition report — the vocabulary that tells you what a catalogue is not saying.

Browse the collection

Shipwreck porcelain is a subject we write about rather than one we stock; the studio publishes twentieth-century Chinese ink painting, not ceramics. If the appeal for you is the evidence of age and the trace of a maker's hand, the same instinct transfers directly to the collection, where the reproductions are made from originals with documented brushwork. Each is a limited-edition archival giclée, hand-numbered, with a Certificate of Authenticity that states exactly what it is.