What a COA Should Actually Tell You

What a Certificate of Authenticity Should Actually Tell You

A buyer’s guide to evaluating the document, the process behind it,

and the right questions to ask before you buy.

by Alejandro E Trimper

Not long ago, in an essay on Collecting Keith Haring's subway drawings published in Incollect Magazine, I made what I thought was a passing observation: a Certificate of Authenticity should not be treated as proof simply because it uses the word "certificate".

That sentence did quiet work in my inbox.

Collectors wrote asking what their own certificates were actually worth. Dealers wrote asking where I drew the line between seller documentation and authentication. Galleries wrote about how often serious documentation gets reduced to a single piece of paper. New buyers, more than anyone, asked the simplest and most important question of all: how do I know what I am holding?

I'll preface this by saying YES, I know some of this will be repetitive. It's not because I like hearing myself talk, so here's my answer.

I have been in the gallery and art advisory business for about 20 years. I am not an art scholar, I am not a lawyer, and I am not the authority on anything except, possibly, my love of Keith Haring's subway drawings, which is a sentence that has transformed my life in ways I had never anticipated. What I am is someone who has watched the same confusion happen to good people, over and over, in living rooms, offices and at art fairs when standing in front of perfectly nice works of art, and so I have finally decided to sit down and write out what I would say if we were all sitting at a dinner party together and the topic came up between the second glass of wine and dessert.

So pretend it has.

A Certificate of Authenticity (COA)can matter a great deal. It is not powerful because of its title. It is powerful, when it is powerful, because of what sits behind it.

In a well-documented sale, a COA is the beginning of a real substantive file. In a thin sale, it is a piece of paper that tries to handle all the documentation by itself. The first is a useful document. The second is a magic trick.

The rest of this essay is just me explaining how to tell which one you have.

If you read nothing else, jump to the questions in Section VI. But the questions will be easier to ask, and the answers easier to weigh, if you understand a few things first.

I. The Two Documents That Are Both Called a "COA"

The art world uses one phrase, Certificate of Authenticity (COA), to describe two pieces of paper that serve very different functions. This is the single biggest source of buyer confusion, and once you see it, you cannot unsee it.

The first kind of COA is a seller-issued certificate or Gallery Certificate. It states the artist, the title, the date, the medium, the dimensions, sometimes a photograph, and a sentence that says, with varying degrees of poetry, we certify this work is authentic. It carries a signature. It carries a date. It looks reassuring because it is designed to look reassuring.

This document is not meaningless. New York's Arts and Cultural Affairs Law §13.01 is direct on this point. When an art merchant sells a work to a buyer who is not an art merchant and furnishes a written certificate or similar instrument, the statute provides that the writing shall be presumed to be part of the basis of the bargain and shall create an express warranty for the material facts stated as of the date of the sale. The Uniform Commercial Code approaches the same issue through §2-313. In plain English, a seller-issued COA can give the buyer contractual recourse against the seller if the work turns out not to be what the certificate says. That is a real protection.

But notice what it is. A seller-issued COA is a promise by the seller. It is not, by itself, independent proof. The person making the certification has a financial interest in the certification being accepted. That is not an accusation. It is a structural fact. It is one of the reasons every other serious market (auditors, appraisers, securities ratings, medical second opinions) figured out a long time ago that the person selling something and the person certifying it probably should not be the same person.

The art market is unusual in not having made that separation routine.

The second kind of COA is an authentication report issued by the artist's estate or foundation, or by an independent 3rd-party expert who writes a scholarly study. These are a different animal. A serious report is usually longer and more specific. It discusses provenance, comparables, materials, technique, inscriptions, condition, publication history, catalogue raisonné status, and the examiner's qualifications. It identifies what was examined, by whom, against what evidence, and with what limits. It does not just say authentic. It explains why the conclusion is supportable. It is signed by someone whose role is defined and whose independence is disclosed.

These are two completely different documents. One is a warranty by a party to the transaction. The other is evidence produced by someone whose job is to weigh evidence. A strong sale can include both. A weak sale often has only the first, dressed up to look like the second.

This is the part that gets people hurt. Not because anyone is lying, necessarily, but because the word certificate on letterhead does a lot of unearned work in the buyer's brain. The brain says: certificate, that sounds official, that sounds settled. The brain is not wrong to do that. The brain is just being efficient. Our job, as buyers, is to slow the brain down for sixty seconds and ask: what is this document, really?

II. The Landscape Has Changed, and No One Sent a Memo

For most of the twentieth century, if you wanted a serious independent opinion on a major modern or contemporary work, there was a place to send it. That landscape is mostly gone for many of the artists collectors most want to buy. Between roughly 2011 and 2014, the leading authentication committees, Warhol, Basquiat, Haring, Pollock-Krasner, the Motherwell-related Dedalus Foundation, all closed or wound down, driven by a combination of ruinous litigation costs and, in some instances, the committees own well-documented transparency and conflict-of-interest problems. The independent International Foundation for Art Research wound down its authentication research service in 2024. The New York legislature tried four times between 2014 and 2020 to pass a shield law that would have protected good-faith authenticators and never passed one. The full arc of how the certificate of authenticity got to its current state, the structural problems with the system that produced it, the shadow exceptions that still get made under the cloak of darkness, and where independent provenance, digital registry, and science-based verification can shift the burden of proof back to evidence, is in my companion piece, What Is a Certificate of Authenticity, Really?. If you want the past, present, and hopeful future of the document, that is the essay to read alongside this one. This piece is the buyers guide. That piece is the context.

What this means for buyers, right now, in the room with a document in their hands, is this. A sentence that begins the foundation authenticated this work warrants a follow-up question. Which foundation? On what date? Through what process? Signed by whom? Was there an active review channel at the time? Was the process transparent, and is that process explained in the documentation? A legacy committee opinion from a period when the channel was open can still mean something. A document presented today that gestures at a foundation whose public position is that it no longer authenticates is doing something else. The buyer is entitled to know which they are looking at.

III. The Single Question That Replaces All Other Questions

Here is the framework I have found useful, and I will give it to you in one sentence.

Does the document show its work?

That is it. That is the whole game.

A document that shows its work tells you who issued it, what they examined, what evidence they relied on, what they found, what they did not find, what remained uncertain, and what relationship they have to the transaction. A document that does not show its work asks you to trust the conclusion without seeing the evidence.

Both kinds of documents can use the word certificate. Only one of them deserves it.

If you remember nothing else from this, remember the next sentence. The right question is not whether a Certificate of Authenticity exists. The right question is whether this Certificate of Authenticity is worth the paper it is printed on. That is not a cynical question. It is the most respectful question a buyer can ask, because it takes the document seriously enough to actually read it.

IV. Reputation Is a Starting Point. Not the Whole Enchilada.

Collectors take comfort from buying from established galleries, and they should. History matters. Relationships matter. A gallery's exhibition record, its scholarship, its clients, and the way it treats its artists are all relevant. Reputation is real evidence.

It's not all the evidence you'll need to know about "the next object".

Reputation is evidence about an institution's past. The certificate in front of you is about a specific work, on a specific day, with a specific chain of facts behind it. The gallery's hundred-year history did not paint the painting. The gallery's beautiful New York City, London, or Paris address did not examine the verso. Those things matter, but they are not the file.

This is the part where I think the smartest thing a buyer can do is the kind of mental exercise that sounds slightly rude on paper and is, in fact, the most useful question in collecting. Ask yourself, quietly:

What would remain true about this work if the dealer's reputation were removed from the file?

That is not hostility. That is hygiene. If the answer is "everything," congratulations, you are looking at a real file. If the answer is "almost nothing," you are not looking at a file. You are looking at the dealer's reputation in a frame.

A serious gallery should not be offended by that question. A serious gallery should be relieved by it, because a serious gallery has built a real file precisely so the buyer never has to take that question on faith.

The cases that make the news, the ones that show up in documentaries and longform magazine pieces and law review articles, all share a common structure. A respected gallery, or a charismatic dealer, or an established name, presents a beautiful object with a thin file, and the reputation is asked to do work that the documents cannot do. That is the pattern. The names change. The pattern does not.

If you want to see the pattern up close, the Made You Look documentary on Netflix is the most efficient way to spend ninety minutes I can recommend on this subject. It is the closest thing to a master class in what reputation-without-documentation looks like from the inside. It will make you a more careful buyer in one evening than this essay can in one read.

And because this section could otherwise sound like a long sigh, here is the inverse story, the kind buyers should look for and sellers should want to produce. Take a work that was twice rejected by a now-closed foundation board during the years that board was operating, stamped "DENIED" on the back twice in red ink, set aside for a decade, and then submitted for review to an independent authenticator whose methodology is published on his website, whose qualifications are disclosed, whose fee structure is public, and who has no financial interest in the underlying market beyond his own reputation for getting it right. He looks at the work, looks at the comparables, looks at the provenance, writes a reasoned opinion explaining how he arrived at his view, and signs it. The painting then goes to auction, and the auction catalogue discloses, openly and in plain language, that the board had previously rejected it and that the independent authenticator subsequently authenticated it. The buyer can read both opinions, see both processes, and decide what weight to give each.

That is what a document showing its work looks like in the wild. It is not unanimous. It is not tidy. It is honest, and the buyer is treated as an adult capable of weighing evidence. The case I am describing is publicly documented in the trade press, and the relevant articles are in the further reading section if you want to see the file work itself out in real time.

V. What a Real File Looks Like

This is the part most buyers actually want to know, and the part the trade is least good at explaining out loud. So here it is, plainly.

A real authentication file usually rests on three legs. Provenance. Scholarly analysis. Technical examination. James Martin, who now heads Sotheby's Scientific Research Department, has called these "the three essential parts of scholarly art authentication," which is a sentence I trust because Martin is one of the few people in this field whose work has held up under the kind of pressure that breaks most reputations.

You will not always have all three. You will not always need all three. But you should be able to tell, from the file in front of you, which legs of the stool are present and which are not.

Provenance: the documented history of the work

Every work has a history. Provenance is how much of that history can be documented, and where it is documented, how much of it can be corroborated.

There is a difference, and this is one of the most important sentences in this essay, between a receipt and a corroboration. A receipt is a piece of paper that says somebody sold something to somebody else. A corroboration is what happens when that receipt can be cross-checked against an independent record: the issuing gallery's own stockbook, a known exhibition catalogue, an artist's records, an estate archive, a contemporary publication.

A receipt by itself is documentation. A receipt that can be corroborated is provenance. The trade often uses the words interchangeably, which is unfortunate, because it lets weak provenance hide inside strong-sounding sentences. Acquired directly from the artist. Beautiful sentence. Means very little without a corroborating record.

Two things I want to say about provenance before I move on.

The phrase "private collection" is not provenance. It can be an understandable privacy label, and there are plenty of legitimate reasons a name should not be printed. But it should not be used to hide a gap. Where names cannot be disclosed publicly, they can usually be disclosed confidentially to an advisor, an auction-house specialist, or a buyer's counsel. Where gaps exist, they should be dated and explained. A gap that is dated and explained is a real provenance with a real soft spot. A gap that is hidden is something else.

Provenance can be wrong, and the honest answer is to say so. Old receipts can describe works that were later swapped, restored beyond recognition, mis-described, or attributed to the wrong studio. Provenance is built by humans, and humans are fallible. The point is not that a strong file makes a work certain. The point is that a strong file makes a work testable. Without it, the buyer has nothing to test.

Some categories of work are genuinely harder than others, and I want to spend a moment on them because they are where most buyer confusion lives.

Take Keith Haring's subway drawings, which I have spent more time with than I have spent with most of my own family. These are works Haring made in the New York City subway, on black paper used to cover expired advertising posters, during a stretch in the early eighties. They were not made in a studio. They were not catalogued at the moment of creation. They were not sold through a primary dealer the way a studio canvas would have been. They were physically taken off the wall, sometimes by passersby, sometimes by collectors who paid the artist, sometimes by people whose later accounts of how they came to own the work are the only record that exists.

A traditional provenance trail does not exist for most of these objects in the way it exists for, say, a Lichtenstein canvas with a Castelli stockbook entry. Pretending otherwise would be a lie. The honest approach is to disclose exactly what is known: how the present owner says they came to acquire the work, when, from whom if known, what supporting records exist, what photographs or letters or recollections support the account, what gaps remain, and what the work itself can tell us through physical examination. That is a file. It is not a perfect file. It is the file that honestly belongs to that category of object.

And every once in a while, with this kind of work, you hit a jackpot. The current owner is the original remover. They have a contemporary photograph. They have a letter. They were there. That is rare and it is wonderful and it should be presented exactly as what it is, which is the strongest provenance this category can produce. A buyer who sees that kind of file should feel lucky. A buyer who is told a vague acquired in the eighties with no supporting record should ask the next question, kindly, and see what comes back.

This is, by the way, where the most important sentence in this whole field lives, because the documentation problem in art is rarely about whether some documentation exists. It is about whether the documentation matches the work it is attached to. Documentation can be entirely truthful about a work without being truthful about the work being sold. An invoice can be real and still describe a different painting. A photograph can be real and still show a different drawing. A foundation letter can be real and still refer to a related work, not the one in the frame. The buyer's job is not to assume the paperwork is fake. The buyer's job is to ask whether the paperwork is actually about the object in the room.

A good seller will help you answer that question. They will line up the documentation against the work and walk you through it. A seller who waves a folder and says it's all in here and then changes the subject is showing you something about themselves, even if they do not realize it.

Scholarly analysis: the argument that the work fits the artist

A meaningful scholarly analysis does not announce that a work "looks right." It identifies the artist-specific basis for the attribution. Period. Materials. Scale. Iconography. Execution. Inscriptions. Comparables. Relationship to documented works. The examiner is named. Their qualifications are relevant to this artist, not to art generally. A specialist in one market category is not automatically a specialist in every artist.

Catalogue raisonné inclusion is one of the most important signals in this category, and it deserves a paragraph of honesty. Catalogues raisonnés are scholarly projects compiled by humans. Some are open and continuously updated. Some are closed. Some are commercial. Some are remarkable works of scholarship and some are not. The weight to give inclusion depends on which project, who edits it, and how its review process works. Inclusion in a well-regarded, scholarly catalogue raisonné is meaningful evidence. Inclusion in a project the buyer cannot evaluate is something else, and it should be evaluated, not just accepted.

When two scholarly opinions disagree, which happens more often than the market likes to admit, the buyer should treat the disagreement as information, not as a vote count. The right question is: what evidence does each opinion rest on, and which body of evidence has held up?

Technical examination: what the materials can and cannot prove

Technical examination is often misunderstood. It rarely proves that a named artist made a particular work. What it can do, very powerfully, is test whether the materials and methods are consistent with the claimed date, place, and practice. Pigments have histories. Papers have histories. Binders, supports, mediums, and commercial products did not exist before specific dates. A claimed 1948 painting that contains a pigment first synthesized in 1973 has a problem that no amount of beautiful paperwork can solve.

Sharon Flescher, who led IFAR for twenty-five years, put the limits well: "Technology is not a miracle and it will almost never prove that a work is authentic, but it can rule out a work as being inauthentic." That sentence should be tattooed on every conservation-lab door. Technical examination is not a magic wand. It is a way of asking the materials to tell the truth about themselves. Sometimes they do, and the answer is reassuring. Sometimes they do, and the answer is the end of the conversation.

Not every work needs a full laboratory campaign. A multi-million-dollar painting may warrant deep technical analysis, legal review, specialist opinions, and provenance reconstruction. A lower-value work on paper may warrant a much narrower file. The credible approach is not to pretend every acquisition requires the same process. It is to disclose what has been done, what has not been done, and why the level of review is proportionate to the work. A seller who skipped the technical examination on a low-six-figure print and tells you so honestly is being more transparent than a seller who handwaves a million-dollar painting through with a sentence on letterhead.

VI. Six Questions to Ask Before You Buy

This is the section to bookmark. Or, if you are a paper person, print it. Or, if you are the kind of collector who keeps a small leather notebook for fairs, write the six questions in the front of the notebook in your own handwriting. I am not picky about format. I am picky about the asking.

Ask these in writing before you acquire a secondary-market work by a deceased artist. Keep the answers with the work. They will be useful to you when you sell the work in twenty years, and they will be useful to the person who buys it from you, which is the kind of paying-it-forward that holds the secondary market together.

1. What is the basis for the attribution to this artist, and what documentation supports it? A serious answer points to specific evidence: provenance records, catalogue raisonné references, prior publications, exhibition history, specialist review, or technical analysis. We believe it is authentic is not evidence. It is a conclusion.

2. Who examined the work, what are their credentials for this artist specifically, and what was the scope of the examination? Ask whether the review was in person or from photographs. Ask whether the examiner inspected the verso, frame, labels, paper, canvas, inscriptions, condition, and materials. Ask whether the conclusion is in writing. A specialist in this artist is a different proposition from a generalist with a good eye.

3. What is the documented chain of ownership, and where are the gaps? A complete answer names documented owners where possible and honestly identifies undocumented periods. A gap is not always fatal. An undisclosed gap is a problem.

4. Has the work been submitted to a foundation, catalogue raisonné project, auction house, estate, scholar, or laboratory before? What was the outcome? A prior decline, refusal, or non-inclusion is not automatically dispositive, but the buyer is entitled to know. Silence on this point is often where risk hides. When a seller offers a document described as a "foundation COA," the question becomes more pointed: which foundation, on what date, signed by whom, through what process, on what evidence?

5. Has the work been examined for materials and technique consistent with the claimed date and medium? Is that examination available in writing? If not, ask whether the price and risk justify commissioning a technical review before closing. The right level of examination depends on the work, but the absence of examination should be disclosed rather than blurred.

6. What written warranty survives the sale, and what happens if the attribution is later credibly challenged? Ask what the seller will put in writing. How long does the warranty last? What evidence triggers a return or rescission right? Who decides what counts as a credible challenge? The warranty is where confidence becomes accountable.

Two practical notes about asking these questions.

First, the way the seller responds to the questions is itself an answer. A seller who welcomes them, makes time for them, walks you through the file, and offers to put answers in writing is telling you something about how they do business. A seller who deflects, jokes them away, makes you feel small for asking, or moves to close the sale faster is also telling you something about how they do business. Pay attention to the second answer more carefully than the first.

Second, asking questions is not adversarial. It is the foundation of trust. The whole reason people enjoy collecting art, when they are lucky enough to do it well, is the conversation. You learn the artist. You learn the period. You learn the gallery. You learn the dealer. Sometimes you learn yourself. A good acquisition is the start of a relationship with the work, with the people around the work, and often with the people who sold you the work. The questions in this section are the beginning of those relationships. A seller who treats them as a beginning is the seller you want to keep buying from.

If the answers come back as some version of trust us, you are not necessarily being defrauded. You may simply be in a transaction that is asking you to take on more risk than the price reflects. That can still be the right decision, at the right price, with the right seller, for the right reason. It should just be a conscious decision, not a misunderstanding produced by a certificate-shaped piece of paper.

VII. The Stuff Worth Keeping (and Why Your Future Self Will Thank You)

A short interlude for the practical collector, because nobody else writes this part down.

Whether you bought the work on the primary market directly from the artist or the artist's gallery, or on the secondary market from a dealer, an auction house, or another collector, here is the basic file you want to keep with the work. Put it in an envelope. Put the envelope in a folder. Put the folder somewhere your future self will find it.

The invoice or bill of sale, with full description, dimensions, medium, date, and price.
The Certificate of Authenticity, if one was issued, plus anything that was attached to it.
Any provenance documentation the seller provided.
Any catalogue raisonné reference, exhibition record, or prior publication.
Any conservation, condition, or technical-examination report.
Photographs of the work front and back, including the verso, any labels, any inscriptions, and any frame markings.
The written warranty, if any, and the seller's contact information.
For works bought from a gallery or estate, the gallery's own stock or inventory number if one was assigned.
For primary-market purchases, anything that ties the work to the studio: photographs with the artist if you have them, a signed copy of an exhibition catalogue, or correspondence about the work.

A complete file at the moment of purchase is the cheapest insurance policy in collecting. It costs nothing. It takes ten minutes. And it is what makes the work resellable, lendable, insurable, and explicable to your heirs, your advisor, your insurer, and the next buyer twenty years from now.

As a market norm, galleries do not introduce buyers to prior owners. Provenance is documented through the file, not through direct contact between the current and previous holders of the work. A serious file should make that documentation legible without needing the buyer to call anyone.

If the seller cannot give you those things at the moment of sale, ask why. The answer may be perfectly valid and legitimate. We are still gathering the foundation paperwork; we will send it in two weeks. Fine. Put that in writing. Then expect the paperwork.

VIII. How Our Gallery Approaches the Issue

I include this because a piece arguing for transparency should be transparent about its author.

Trimper Gallery does not authenticate artworks. We have never authenticated artworks. We do not offer opinions on authenticity. When we sell a secondary-market work, our job is to identify the basis for the attribution, disclose the documents that accompany the work, and be clear about what we have and what we have not done.

Where credible estate, foundation, catalogue raisonné, scholarly, scientific, or laboratory documentation exists, we want the buyer to see it, and do our best to ensure it's included as part of the file. Where further review is appropriate, we work with the buyer to locate the appropriate specialists rather than pretending to stand in their place. Where a seller's warranty is part of the transaction, it should be in writing, in language the buyer can understand, signed by the seller, and kept with the file.

This is not the only responsible way to operate. Plenty of galleries produce substantive documentation of their own and stand behind it well, and I have a lot of respect for those galleries. The principle I want to be clear about is the one at the center of this essay. The seller and the authenticator are different roles. A gallery can sell, disclose, warrant, and assist with due diligence. It should not blur those functions into a document that looks independent but is only the seller's own conclusion in nicer typography.

IX. The Reason Any of This Matters

I want to close with the part that does not show up in law review articles.

The reason people collect art is because, at its best, collecting is one of the few transactions in adult life where you get to fall a little in love (maybe a lot in love) with an object and then take it home. That is not a small thing. It is the entire point. Look at the old gallery photographs from the sixties and seventies, the ones with the artists, dealers, and the collectors all standing around the work, drinks in hand, laughing at something nobody remembers anymore. Those people were doing something serious and something special. They were also having a wonderful time, and, most importantly, they were creating a memory that would last a lifetime.

Somewhere along the way, parts of this market got serious in the wrong way. The fun got squeezed out. The paperwork got worse. The transparency got worse. The pressure tactics got worse. Buyers started feeling stupid for asking questions, which is the surest sign that something has gone wrong in any market, because the people asking questions are the people the market needs most.

I'm trying to pose an argument that goes against that drift. Not because I think the art world is broken. I do not (at least not beyond repair). Most of the people I have met in this business over twenty years are exactly what you would hope they are: passionate, curious, occasionally eccentric (sometimes very eccentric), deeply committed to the work and the artists and the collectors who care. The brush-off culture is the exception, not the rule. But the exception has gotten loud, gained a lot of power and influence, and the rule has gotten quiet. A buyer's guide to documentation is my small way of pushing the lever back to center, if only for those who take the time to read this.

The questions in Section VI are the practical version of that argument. They are the questions I wish every buyer felt entitled to ask, without apology, in any gallery in any city, of any dealer at any level. They are the questions a good seller hopes to be asked, because the answers are how trust gets built and how the work becomes a story you will be telling at dinner parties for years.

Transparency is not the opposite of romance (ask anyone who's bought from us). It is the condition and necessary foundation for romance to even exist. The painting you love at first sight is more lovable, not less, when the file behind it is complete, and the conversation around it is honest. The best collecting moments I have witnessed in twenty years have all looked the same: a buyer in front of a work, a seller in front of a file, both people enjoying themselves, both people learning something, both people walking away feeling like the transaction made them slightly better collectors and slightly better human beings than they were that morning.

That is what this is supposed to feel like. If you are not getting that, you are entitled to ask for it, because at the end of the day, you are paying for it.

And if the document in front of you does not show its work, you are entitled to ask why.

Search This Blog

What a COA Should Actually Tell You

I. The Two Documents That Are Both Called a "COA"

II. The Landscape Has Changed, and No One Sent a Memo

IV. Reputation Is a Starting Point. Not the Whole Enchilada.

V. What a Real File Looks Like

Provenance: the documented history of the work

Scholarly analysis: the argument that the work fits the artist

Technical examination: what the materials can and cannot prove

VI. Six Questions to Ask Before You Buy

VII. The Stuff Worth Keeping (and Why Your Future Self Will Thank You)

VIII. How Our Gallery Approaches the Issue

IX. The Reason Any of This Matters

Further reading, for the curious

Labels

Comments

Popular posts from this blog

Three Chefs, One Night, No Encore: A Dinner at Platform

We Gave Away the Most Important Relationship, Our Clients