Buying Sculpture at Auction: Casts, Editions, Fabrication and What You Actually Own

Buying sculpture at auction asks a different set of questions from buying a painting. A canvas is a single object whose risk file is provenance, attribution and surface. A three dimensional work is frequently one of a numbered series, made by hands other than the artist's, in a material with its own decay curve, and it arrives with installation, storage and transit costs a framed work never carries. The Art Basel and UBS Global Art Market Report 2026 put the global market at 59.6 billion dollars in 2025 and recorded purchasing habits spreading across mediums. Collectors fluent in painting are now bidding on objects while carrying painting era habits with them. This article sets out precisely what changes: what a cast number establishes, where French law draws the line between an original and a reproduction, what a foundry mark proves, and what the object costs to own once the hammer has fallen.

Key facts:

• Under Article R.122-3 of the French Code de la propriété intellectuelle, a sculpture edition limited to twelve numbered casts, artist's copies included, counts as an original work of art. From the thirteenth cast, the object is a reproduction.
• Décret 81-255 of 3 March 1981 requires every reproduction or aftercast made since it took effect to be marked "Reproduction" in a visible and indelible manner. The Musée Rodin reads "visible" as immediately legible, without handling the object or turning it upside down.
• The twelve cast convention is 8 casts numbered 1/8 to 8/8 plus 4 artist's proofs numbered I/IV to IV/IV, fixed by the décret of 10 June 1967 applying the law of 6 January 1966.
• The Art Basel and UBS Global Art Market Report 2026 recorded 59.6 billion dollars in global art sales for 2025, up 4 percent, with public auction sales at 20.7 billion dollars, up 9 percent.
• All risk transit cover for fine art commonly runs 0.3 to 1.0 percent of declared value, and professional custom crating for a single object commonly costs 150 to 400 dollars before specialist handling.

A season that turned three dimensional

The autumn 2026 calendar has an unusual amount of weight in it. In September 2026, the 37th Praemium Imperiale went to Jenny Holzer for painting and to Andy Goldsworthy for sculpture, according to Artnet News. Qatar Museums announced the Doha Pavilion: Gerhard Richter, a permanent site specific structure the artist designed as a free standing work of art and architecture to house his paintings and sculpture, realised with Selldorf Architects and unveiled on 20 November 2026. Art Basel's editorial programme has spent the season inside studios rather than salerooms, publishing Studio Roll: Sagarika Sundaram on 17 September 2026 and a visit to Drake Carr's Brooklyn studio on 10 September 2026, both centred on artists who work in three dimensions. Ursula, the magazine published by Hauser and Wirth, devoted part of its eighteenth issue to Ina Jessen's reading of Dieter Roth's use of edible materials, a subject that is about nothing so much as what happens to an object over time.

The market data sits underneath that editorial turn. The Art Basel and UBS Global Art Market Report 2026, prepared by the cultural economist Clare McAndrew of Arts Economics, recorded global art sales of 59.6 billion dollars in 2025, a rise of 4 percent and the first growth after two consecutive years of decline. Public auction sales reached 20.7 billion dollars, up 9 percent, while the dealer sector grew 2 percent to 34.8 billion dollars and private sales fell 5 percent to 4.2 billion dollars. Fine art lots sold above 1 million dollars increased 21 percent year on year. UBS separately reports that paintings remain the most purchased medium and the largest by value, while purchasing habits have diversified across mediums, artist categories and buying channels, with millennial collectors most active in prints, photography and works on paper.

That diversification is the practical reason buying sculpture at auction has become a live question. A collector who has spent fifteen years buying paintings has an internalised checklist, and almost none of it transfers. Buying sculpture at auction puts four new questions in front of that collector at once: how many of this object exist, who was authorised to make it, what the surface is telling you, and what the thing will cost to keep.

What buying sculpture at auction asks that a painting does not

Those five rows are the structure of this article. Each one is treated in order below.

An edition you can walk around: what a cast number means

A print edition and a sculpture edition use the same arithmetic and mean different things. A print edition is pulled from one matrix in a single campaign, and the numbering records position within that campaign. A bronze edition records how many casts an artist or an estate authorised from a model, and those casts are frequently produced over years or decades rather than in one run. An edition of 8 begun in 1962 may have had its final cast poured in 1989 from the same plaster, with no deception involved and no entry in the catalogue that makes the gap obvious.

A cast number is the fraction inscribed on a sculpture, most often on the base or an inner edge, that records the object's position in an authorised edition. It establishes two things and only two: that the object was intended as part of a declared series, and where in that series it sits. It does not establish who poured it, when it was poured, or whether the edition was already complete when this cast was made. Those are separate questions with separate evidence, and buying sculpture at auction means putting all three to the house.

The convention that the market runs on comes from French tax and cultural law. The décret of 10 June 1967, applying the law of 6 January 1966, limited an original edition to 8 casts plus 4 non commercial artist's proofs. An artist's proof, numbered in Roman numerals as I/IV to IV/IV, is a cast reserved outside the commercial edition for the artist, the estate or an institution. It is part of the twelve, it is an original under the law, and it was not originally intended for sale. Artist's proofs do reach the market, and a catalogue entry that describes a lot as an artist's proof without saying which of the four it is has told you less than it appears to.

The practical consequence for buying sculpture at auction is that the edition declaration in a catalogue is a claim about a population, not about the object in front of you. A lot described as "number 6 from an edition of 8" is asserting that seven other casts exist. Ask what the catalogue raisonné says about the edition, whether the four artist's proofs are accounted for, and whether any cast in the series was made after the artist's death.

Twelve casts: the legal line between an original and a reproduction

French law draws a hard numerical line, and because France is where the modern bronze edition convention was codified, that line is the reference the European trade catalogues against. The French Sculpture Census states the rule plainly: "Under French law, the first twelve casts of a bronze edition are original works of art. Starting with the 13th cast, they are reproductions and must bear this label in a visible place on their exterior."

The statutory anchor is Article R.122-3 of the Code de la propriété intellectuelle, which, in the Musée Rodin's own formulation, "stipulates that editions of sculptures limited to twelve numbered casts, including artist's copies, are considered to be original works of art." Twelve is the ceiling for the whole edition, artist's proofs included. An edition of 12 numbered casts plus 4 proofs is 16 objects, and the last four are not originals under the French rule however the catalogue describes them. Anyone buying sculpture at auction from a French sale should treat twelve as the number that decides status, and should ask which national rule the cataloguing house applied when the sale sits elsewhere.

The marking obligation is where the law becomes something a bidder can physically check. Décret 81-255 of 3 March 1981, aimed at fraud in transactions of works of art and collectables, requires at Article 8 that any facsimile, aftercast, copy or other reproduction be described as such, and specifies that the terms "reproduction" and "aftercast" must appear on invoices and in catalogues and articles. Article 9 requires that any such object executed after the décret took effect be marked "Reproduction" in a visible and indelible manner. The Musée Rodin's reading of "visible" is the operative standard and it is strict: immediately legible, a requirement that "is not fulfilled if the search involves handling the object or turning it upside down." The word is to be inscribed in hollow or high relief on the base or on the figure itself.

Two consequences follow for a bidder. First, a bronze offered as an original that carries a visible "Reproduction" mark is describing itself, whatever the lot note says. Second, the absence of the mark on a post 1981 aftercast is itself a legal defect in the object, and under the Musée Rodin's position on Rodin material, casting without that mark "constitutes an infringement of Rodin's moral right."

These rules are reinforced professionally as well as statutorily. The Code de déontologie des fonderies d'art of 18 November 1993 was drafted by the Syndicat général des Fondeurs de France with the Syndicat des sculpteurs, the Chambre nationale des Commissaires-priseurs and the Comité des Galeries d'art, and approved by all four. When a foundry, an auctioneer or a gallery in France describes an edition, that code is the professional standard they are describing it against.

Lifetime, posthumous and unauthorised: reading the date of a cast

The date on a sculpture is usually the date of the model. A work catalogued as 1908 may have been cast in 1908, in 1952, or in 1997, and the three carry different status. A lifetime cast was produced with the artist's involvement. A posthumous cast was produced by an estate or a foundation from an authorised model after the artist's death, and remains an original under the French rule as long as the total edition stays within twelve. An aftercast is made from an existing cast rather than from the original model, loses definition in the process, and is a reproduction.

The Musée Rodin case is the clearest worked example in the field, and the museum publishes its own position for exactly that reason. Under Decree 93-163 of 2 February 1993, consolidated on 7 December 2005, the museum limits its original editions to twelve casts numbered 1/8 to 8/8 and I/IV to IV/IV, counting the editions that already existed. Because those original editions are in most cases complete, the museum states that "any new edition of these sculptures in bronze can only be reproductions." It sells reproductions itself, and casts them in resin rather than bronze specifically to prevent confusion. It refuses all use of the moulds and original plaster models from Rodin's studio now in its collections, and warns that any claim that it has authorised such use "can consequently only conceal an attempt to sell a work under false pretences."

The museum also records the commercial mechanism that makes this a live risk rather than a historical one. It reports a growing number of bronze reproductions and aftercasts whose appearance fosters confusion with authorised casts, and notes that these are "often accompanied by documents, notably certificates attesting to their alleged authenticity." The Thinker, The Age of Bronze and the Monument to the Burghers of Calais are the examples it names. A certificate is a document produced by whoever chose to produce it, and on a cast whose date postdates the model by decades it proves nothing on its own.

Moral rights sit behind all of this and do not expire. Article L.121-1 of the Code de la propriété intellectuelle gives an artist the right to respect for their name, their standing and their work, and that right is perpetual, inalienable and imprescriptible. An estate can therefore act against a cast made today from a model made a century ago. For anyone buying sculpture at auction, that is a reason to establish the date of the pour before trusting the date of the model.

Who made it: foundries, studios and the authorisation trail

Fabrication by other hands is normal in sculpture and is not a defect. Bronzes are poured by foundries, steel is fabricated by contractors, and large scale work is produced by studios of assistants under an artist's direction. Jeff Koons's Rabbit, the 1986 stainless steel work that sold for 91.1 million dollars at Christie's New York on 15 May 2019 and set the record for a work by a living artist, was fabricated rather than hand made, and nobody treats that as a flaw. What carries value is the authorisation trail, and each document in it proves something narrow.

A foundry mark is a stamp or cachet applied by the foundry that cast the object, naming the workshop and sometimes dating the pour. It establishes where the object was made. Elisabeth Lebon's Dictionnaire des fondeurs de bronze d'art, France 1890 to 1950, listed in the French Sculpture Census bibliography, is a standard reference for reading French foundry marks, and a mark from a foundry that had closed before the catalogued date of the cast is a straightforward contradiction. A signature in the cast establishes that the signature was in the model when the object was poured, which says nothing about who authorised the pour. A certificate of authenticity is a statement by its issuer, and its weight is exactly the weight of the issuer: an artist's foundation with a published edition register is one thing, an unnamed expert is another. A catalogue raisonné entry is the strongest of the four, because it places this specific cast inside a documented edition rather than asserting quality in the abstract. The distinction between what each proof actually establishes is worth reading in full before bidding, and our note on whether a certificate of authenticity art or a catalogue raisonné entry carries more weight sets out where each one fails.

None of the four establishes authenticity on its own, and a house that tells you otherwise is overreaching. What a serious catalogue entry does is show its working: the edition size, the cast number, the foundry, the date of the pour where it is known, the catalogue raisonné reference, and the ownership history. Where one of those is missing, the entry should say it is missing. Buying sculpture at auction is in large part the practice of reading that working.

Condition in three dimensions, and patina as intent

A condition report on an object reads differently from one on a canvas because the failure modes are different. The report on a painting concentrates on plane and surface: craquelure, relining, retouching, varnish. A report on a sculpture has to account for a structure that carries its own weight, and for a surface that was frequently designed rather than acquired.

Patina is the surface colouration of a bronze, and the central distinction is between patina as intent and patina as age. A chemical patina applied at the foundry to the artist's specification is part of the work. Oxidation acquired over eighty years outdoors is a change to the work. Corrosion that has pitted the metal is damage. All three can look superficially similar in a catalogue photograph, and the difference between them can be the difference between a sound object and a compromised one. A report that says "fine overall patina" without saying which of the three it is describing has not answered the question.

The other checks a three dimensional report should carry are structural. Joins and welds on a fabricated work are load bearing and the commonest site of stress failure. Internal armatures in plaster, resin and mixed media works corrode invisibly. Plinths and mounting hardware are frequently later, and a replaced plinth changes both the presentation and the object's relationship to its own edition. Previous restoration on a cast surface is harder to detect than on a canvas, because a well executed repatination covers the evidence of the repair beneath it. Our guide to how to authenticate a painting through its condition report covers the reading method; on an object, apply that method to structure and surface separately.

The governing principle is simple and it is the one a serious house will hold to. The condition report is the document that binds. A catalogue description presents a work, while a condition report records its state. Where the two diverge, the report is the one that governs. When buying sculpture at auction without a physical inspection, request the report before bidding, ask directly about joins, armature, plinth and repatination, and weigh the silence of a report that will not address them before bidding.

Materials that will not hold still

Twentieth and twenty first century sculpture is made of things museums are still learning to keep. Plastics are the sharpest case. The Getty Conservation Institute has run a dedicated Preservation of Plastics project since 2013, managed by the conservator Anna Laganà, and its own statement of the problem is blunt: "many of the plastics used in these works can deteriorate with surprising suddenness. Common signs of deterioration include discoloration (yellowing or opacifying), crazing and cracking, warping, becoming sticky (as plasticizers migrate out of the bulk material and onto their surfaces), and, in extreme cases, turning completely to powder." The institute records the degradation of plastic objects as a growing problem for museums and galleries for more than twenty-five years, and singles out the risk to conservators and collectors of rapid disintegration with very little advance warning. Tate's COMPLEX project on the degradation of complex modern polymeric objects applies a system dynamics approach to polymer degradation in order to produce evidence based strategies for storing and displaying plastic objects, with the explicit aim, in Tate's own words, of "evidence-based strategies for storing and displaying plastic objects in museums, to minimise inevitable changes". The degradation of Naum Gabo's plastic sculptures was the original catalyst for that line of research.

These works remain entirely collectable, and the diligence question changes with them. Condition on an unstable material describes a trajectory measured over years. Buying sculpture at auction in such materials starts with establishing what the material actually is. Ask what the storage and display conditions have been. Ask whether the artist or the estate has a published position on replacement, refabrication or exhibition copies, because for some artists that position exists and it governs what a future conservator is permitted to do.

Organic and deliberately perishable material takes the same logic further. Ina Jessen's reading of Dieter Roth in the eighteenth issue of Ursula treats the edible as a deliberate artistic argument rather than a conservation accident, and works of that kind are bought in full knowledge that the object will change. What a house can properly promise about such a work is what the condition report records on the day it was written. Stability sits outside what any house can promise. A house that implies otherwise is taking on a liability it cannot carry, and a buyer relying on that implication has no real recourse.

What the object costs after the hammer

The hammer price is the smallest interesting number when buying sculpture at auction. The buyer's premium comes first: at LLB Auction it is 20 percent, disclosed before the sale rather than assembled at checkout. Then come the costs a framed work does not generate.

Consider a representative case. A bronze catalogued as number 6 from an edition of 8, 62 centimetres high on a marble plinth, hammers at 12,000 euros. The 20 percent buyer's premium brings the invoice to 14,400 euros. Professional custom crating for a single object of this scale commonly runs 150 to 400 dollars in materials and labour, and a bronze on a separate plinth usually needs two crates rather than one. All risk transit cover typically costs 0.3 to 1.0 percent of declared value, so roughly 43 to 144 euros on this invoice, and the practical guidance from specialist shippers is that anything above about 5,000 dollars in declared value warrants a fine art carrier rather than a general courier. Add domestic delivery with two people rather than one, because the plinth and the bronze are lifted separately. The object lands somewhere between 15,000 and 15,600 euros before it is placed. Specialist shippers commonly put total logistics at 3 to 8 percent of value for gallery grade work.

Scale changes the arithmetic while leaving the categories the same. An outdoor work needs an engineered foundation: specialist installers describe a reinforced concrete pad or pier system designed by a structural engineer against the sculpture's weight, height, wind load and local frost depth. That is a construction cost with a lead time, not a delivery charge. Storage is priced by volume, so an object occupies several times the storage cost of a canvas of comparable value, every year it is held.

These costs bear on resale in a way they do not for paintings. A buyer for a two metre steel work is a buyer with the space, the access and the rigging budget for a two metre steel work, and that population is smaller than the population of buyers for a framed work at the same price. Nothing here predicts what a work will fetch. It describes who can physically take delivery of it, which is the constraint that shows up first when an object returns to the market.

The pre-bid checklist for buying sculpture at auction

Run these ten points against any three dimensional lot before buying sculpture at auction. Each one is a question a house should be able to answer in writing before the sale closes.

1. Edition size and cast number. What is the declared edition, which cast is this, and does the total including artist's proofs stay within twelve?
2. Artist's proofs. If the lot is a proof, which of the four is it, and are the others accounted for?
3. Date of the pour. Is the cast a lifetime cast, a posthumous cast from an authorised model, or an aftercast? The catalogue date is usually the date of the model.
4. Marking. Does the object carry any "Reproduction" mark, and if the work postdates 3 March 1981 and is an aftercast, why not?
5. Foundry. Which foundry cast it, what is the mark, and was that foundry operating at the catalogued date?
6. Catalogue raisonné. Is this specific cast recorded, and under what number?
7. Structure. What do the joins, welds, armature and internal supports look like, and has any of it been repaired?
8. Surface. Is the patina original to the foundry, acquired over time, or restored, and does the condition report say which?
9. Plinth and mounting. Is the base original, and is any mounting hardware included in the lot?
10. Delivery. What are the crated dimensions and weight, what does transit cost, and what does installation require?

A house that answers all ten in writing has given you a basis for a bid. Where several of the answers are unavailable, weigh that gap into the price you are prepared to pay. The broader due diligence behind every lot follows the same logic across provenance, attribution and condition.

FAQ: buying sculpture at auction

How can I tell if a bronze is an original or a reproduction?

Start with the count. Under Article R.122-3 of the French Code de la propriété intellectuelle, an edition limited to twelve numbered casts, artist's copies included, consists of original works; from the thirteenth cast the object is a reproduction. Then check the object itself. Décret 81-255 of 3 March 1981 requires reproductions and aftercasts made since it took effect to be marked "Reproduction" visibly and indelibly. Finally, confirm the cast against the catalogue raisonné and the foundry mark. Buying sculpture at auction without those three checks leaves the question open.

What does posthumous cast mean, and is it still an original?

A posthumous cast is one produced after the artist's death, by an estate or foundation, from an authorised model. Under the French rule it remains an original work of art provided the whole edition, artist's proofs included, stays within twelve numbered casts. An aftercast is different: it is taken from an existing cast rather than the original model, loses surface definition, and is a reproduction requiring the visible "Reproduction" mark.

What is an artist's proof in sculpture?

An artist's proof is a cast held outside the commercial edition for the artist, the estate or an institution. The décret of 10 June 1967, applying the law of 6 January 1966, set the standard structure at 8 numbered casts plus 4 artist's proofs, the proofs marked I/IV to IV/IV in Roman numerals. They are originals under French law. When one is offered while buying sculpture at auction, ask which of the four it is and where the other three sit.

What should a sculpture condition report cover that a painting report does not?

Structure and mounting. A sculpture condition report should record joins and welds, the state of any internal armature, corrosion as distinct from intended patina, the originality of the plinth, and any previous repatination, which conceals repairs more effectively than retouching does on a canvas. Ask explicitly whether the patina is original to the foundry, acquired over time, or restored, because a single phrase such as "fine patina" does not answer that.

Does the artist get a royalty when I resell a sculpture?

In the European Union and the United Kingdom, the artist's resale right applies to qualifying resales of original works of art through an art market professional, and an original sculpture edition within the legal cast limit qualifies. Rates, thresholds and the statutory cap vary by jurisdiction, and the treatment of a specific lot depends on where the sale takes place. Confirm the position per sale with the house before bidding.

What does buying sculpture at auction really cost beyond the hammer price?

Budget the buyer's premium first; at LLB Auction it is 20 percent, disclosed upfront. Then add crating, which commonly runs 150 to 400 dollars per crate for professional work, all risk transit cover at 0.3 to 1.0 percent of declared value, specialist handling, and installation. Specialist shippers put total logistics at 3 to 8 percent of value for gallery grade work, and an outdoor piece adds an engineered foundation designed by a structural engineer.

How LLB Auction approaches three dimensional lots

The house's approach to buying sculpture at auction follows from the same rejection discipline it applies everywhere: roughly 40 percent of submissions do not clear intake, and an edition question that cannot be documented is one of the reasons a lot does not reach a sale.

Intake and documentation. Per lot due diligence covers certificate verification, ownership history and conservation records, and on an editioned object that means the edition declaration, the cast number and the foundry attribution are checked before the lot is catalogued rather than asserted afterwards.

Condition reporting. Every lot carries a professional three page condition report. On a three dimensional work that report addresses structure, surface and mounting separately, and where the evidence is incomplete the report records the gap rather than smoothing it over.

Fees and delivery. The buyer's premium is 20 percent and the seller's commission 10 percent, both disclosed before the sale. Timed online sales run 7 to 14 days on the house's own platform, with coordinated worldwide shipping arranged after settlement. Typical lots run 800 to 50,000 euros.

Register at llb-auction.com to receive catalogues and condition reports ahead of each sale. Ask your questions before the sale closes. We have answers, and where we do not, the report says so.

Conclusion

The checks that protect a painting collector were built for unique objects on a plane, and they do not cover a numbered cast in three dimensions. The twelve cast rule in Article R.122-3, the visible marking obligation in Décret 81-255, the difference between a lifetime cast and an aftercast, the separation of patina as intent from patina as corrosion, and the logistics that begin the moment the hammer falls are the second set of checks, and they are learnable in an afternoon. Alberto Giacometti's L'Homme qui marche I, whose second cast reached 65 million pounds with premium at Sotheby's London on 3 February 2010, and a 12,000 euro bronze in a timed online sale raise the same questions in the same order, at very different figures.

Buying sculpture at auction rewards the collector who asks the edition question first and the price question second. Establish how many of the object exist, who authorised its making, what the surface is actually recording, and what it will cost to bring home and keep. A house that will answer those four questions in writing has earned a bid.

Also worth reading:

• Provenance, attribution and condition: the due diligence behind every lot
• How to authenticate a painting through its condition report
• Certificate of authenticity art or catalogue raisonné: which proof counts
• Attributed to vs studio of vs circle of: reading the attribution ladder
• When science enters the room: testing a contemporary work
• How to buy and sell art at auction, without the markup theatre

Sources:

• Respecting Rodin's moral right: a warning to collectors about the notion of authenticity : Musée Rodin
• Legal background on original sculptures and reproductions : French Sculpture Census
• The Art Basel and UBS Global Art Market Report 2026 : Art Basel and UBS, Arts Economics, 2026
• Art market research and the Survey of Global Collecting : UBS, 2026
• Preservation of Plastics : Getty Conservation Institute, 2013 to present
• COMPLEX: the degradation of complex modern polymeric objects in heritage collections : Tate
• Degradation of Naum Gabo's plastic sculpture : Tate Papers
• U.K. pushes to standardize auction data, and more industry intel : Artnet News, 11 September 2026
• Art Basel Stories : Art Basel, September 2026
• Ursula, issue 18 : Hauser and Wirth, 2026
• Jeff Koons's Rabbit sets a new record for a living artist : Artnet News, 16 May 2019
• L'Homme qui marche I : Wikipedia
• International sculpture shipping and installation logistics guide : Y Sculptures
• Insurance for shipping artwork : Anthony Wakefield and Co, 2025