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The short answer. Read an auction catalogue entry in this order: zoom into the photographs (front and back), decode the attribution line ("Attributed to", "Studio of", "Circle of" and "After" each claim less than the artist's bare name), check the description (date, medium, size, signature), then the provenance, exhibition and literature, ask for the condition report, and only then look at the estimate. Finally, convert the hammer price into what you will actually pay: at Sotheby's the buyer's premium is 28% of the hammer price up to $2 million in New York or £1.5 million in London, before tax. Decide your maximum from your total budget, not from the estimate.
This is the practical, step-by-step tutorial. The bidding itself — absentee, telephone and online bids, reserves and increments — is in our first-timer's guide to bidding at auction.
Step 1 — Start with the photograph, not the words
Catalogue photographs are professionally lit and colour-balanced to show the work at its best. That is standard practice, not deception, but it means the photograph is not the object.
- Zoom to full resolution. Look for cracks, repaint, stains, edge and frame damage. The text may describe condition diplomatically; a zoomed photograph is blunter.
- Look at the verso if shown. Gallery labels, customs stamps, exhibition tags and old owners' marks live on the back. That is provenance evidence.
- Compare with the same artist's other lots. A picture that looks too saturated or too clean beside its peers sometimes reflects heavy restoration.
If a photograph cannot be enlarged, ask the specialist for more images before you bid.
Step 2 — Decode the attribution line
The sentence that names the maker is written in a fixed vocabulary, which each house defines in the glossary or "explanation of cataloguing practice" printed in its catalogues and conditions of sale. Read that glossary for the sale in front of you; the usual hierarchy, from strongest to weakest claim, is:
| Wording | What the house is claiming |
|---|---|
| Artist's full name | In the house's opinion, a work by the artist — the strongest claim |
| "Attributed to" | Probably by the artist, but less certain |
| "Studio of" / "Workshop of" | Made in the artist's studio, possibly under supervision |
| "Circle of" | By an unidentified hand closely associated with the artist |
| "Follower of" / "Manner of" | In the artist's style, by a contemporary or later hand |
| "After" | A copy of a known work by the artist |
The price gap between the bare name and "After" is not a detail: it is the whole commercial proposition of the lot. If you are unsure which category a lot falls into, ask the specialist directly and keep the answer in writing.
Step 3 — Read the lot description slowly
The description follows a standard order: title; date (or "circa"); medium and support; dimensions; signature, date and inscriptions with their location; edition details.
- "Circa" means the date is approximate. For artists valued by period, ask which period the house places the work in.
- Medium. "Oil on canvas" is clear; "mixed media" is vague and matters for both value and survival — see what art survives a century.
- Size. Within one artist's output, scale is often a major driver of value.
- Signature. "Signed lower right" is normal; "signed verso" is common; "inscribed" but not signed is weaker; unsigned needs the attribution confirmed.
- Edition. "Edition of 50" tells you the run; artist's proofs (AP) sit outside it.
Step 4 — Provenance
- Named owners with dates ("Galerie X, Paris, 1971") are the strongest entries.
- "Private collection, Europe" is generic: acceptable alongside other detail, weak on its own.
- "By descent" means it stayed in one family. If you are consigning a family piece yourself, give the specialist each generation's name and dates; a family tree built on a genealogy service such as MyHeritage makes that line far more specific than a bare "by descent".
- "Acquired from the above" links entries; an unbroken chain beats one with gaps.
- 1933–1945. For European works of the right age, reputable houses address this period explicitly. An entry that skips it is a question to ask, not an oversight to ignore — the background is in looted art and the Washington Principles.
How much each kind of document is actually worth is covered in what the paperwork actually proves.
Step 5 — Exhibition and literature
Exhibitions list public shows the work appeared in; literature lists publications that illustrate or discuss it. The most important literature entry is the artist's catalogue raisonné. Inclusion is one of the strongest authentication signals available; absence where one exists is not automatically fatal (it may pre-date the work's discovery) but is a question for the specialist. For artists without a catalogue raisonné, exhibition history at recognised institutions does similar work.
Step 6 — Ask for the condition report
The catalogue text is not the condition report. Houses prepare a separate report on request, and it is the most useful document most new buyers never read. Look for:
- Inpainting or restoration — small amounts are normal on old works; extensive retouching affects value.
- Lining — a second canvas added for support; routine, but evidence of past intervention.
- Craquelure — stable fine cracking is normal; "unstable" or "flaking" is serious.
- Tears, losses, abrasion — and where they are: damage in the focal area matters more than at the edge.
- UV examination — restoration shows differently under ultraviolet light.
"Good condition consistent with age" says little; a report that lists specific issues shows someone looked closely. The condition report is not a warranty, and the conditions of sale usually say so — for anything significant, inspect in person or commission an independent report. The vocabulary is decoded in condition grading: what the words actually mean.
Step 7 — The estimate
The estimate ("$40,000–60,000") is the house's working view of the likely price. The reserve — the confidential minimum the seller will accept — is generally set at or below the low estimate.
- A narrow range suggests the house has good comparables.
- A wide range signals uncertainty, an unusual work, or a volatile market.
- "Estimate on request" appears on top lots.
- A lot selling at the low estimate says demand was modest; multiples of the high estimate mean competition beyond expectations — or a deliberately low estimate.
Step 8 — Convert the hammer price into what you will pay
The hammer price is not the price. Each house adds a buyer's premium, tiered so the rate falls as the hammer rises, plus taxes on the premium where they apply. Current published schedules (read on the houses' own pages, 16–17 October 2026):
| House (saleroom) | First tier | Second tier | Above | Source |
|---|---|---|---|---|
| Sotheby's (New York) | 28% to $2,000,000 | 22% to $8,000,000 | 15% | Sotheby's Help Centre |
| Sotheby's (London) | 28% to £1,500,000 | 22% to £6,000,000 | 15% | Sotheby's Help Centre |
| Sotheby's (Paris, Cologne, Milan) | 28% to €1,750,000 | 22% to €7,000,000 | 15% | Sotheby's Help Centre |
| Phillips (London), standard | 29% to £1,500,000 | 22% to £6,000,000 | 15% | Phillips rate sheet, effective 12 April 2026 |
| Bonhams (UK), sales from 1 October 2026 | 30% to £25,000 | 28% to £500,000; 25% to £1m; 21% to £5m | 14% | Bonhams UK page |
Sotheby's charges wine and spirits differently: 24% on all hammer prices plus a 1% overhead premium. Bonhams' wine, coins and motor cars also keep their own schedules. Phillips offers lower "Priority Bidding" rates (25%, 20% and 14%) to bidders who meet the conditions in its conditions of sale.
Worked example 1 — a single tier. $100,000 hammer at Sotheby's New York: premium 28% × $100,000 = $28,000; you pay $128,000 plus any sales tax, shipping and insurance.
Worked example 2 — two tiers. £2,000,000 hammer at Sotheby's London: 28% × £1,500,000 = £420,000, plus 22% × £500,000 = £110,000; premium £530,000; total £2,530,000 before VAT. The premium is calculated band by band, not at one rate on the whole price.
Worked example 3 — banded, with VAT. £40,000 hammer at Bonhams UK (from 1 October 2026): 30% × £25,000 = £7,500, plus 28% × £15,000 = £4,200; premium £11,700 (an effective 29.25%); VAT at 20% on the premium, as Bonhams' UK page states, adds £2,340; total £54,040. If the lot is marked for artist's resale right, add 4% of the hammer (£1,600) under the UK scale — the royalty is explained in auction fees: what you actually pay.
Work backwards from your budget. If €100,000 is your all-in limit at Sotheby's Paris, your maximum hammer before tax and shipping is €100,000 ÷ 1.28 = €78,125. At a house charging 29% it is €100,000 ÷ 1.29 = €77,519. Bidding your budget on the hammer is the classic first-timer's mistake.
Step 9 — Choosing where to buy
The big three houses publish their schedules; smaller and regional houses and online platforms set their own, and they vary widely. Do not assume a smaller house is cheaper: Bonhams' rate from 1 October 2026 on the first £25,000 (30%) is higher than Sotheby's first tier (28%). Read the conditions of sale for the specific auction every time, because rates differ between houses, salerooms and sale categories, and they change.
Step 10 — Questions to ask the specialist before bidding
- May I have the full condition report, and can we discuss anything unclear?
- Is the provenance file complete, and what about any gaps (especially 1933–1945)?
- What is the authentication evidence — catalogue raisonné, foundation, estate?
- Are there export restrictions or heritage laws that affect moving the work? See objects you can own but cannot move.
- What will my total invoice be, including premium, taxes and any resale royalty?
- What are the shipping options and costs?
How quickly and clearly a house answers is itself information.
Frequently asked questions
What does "attributed to" mean in an auction catalogue?
That the house thinks the work is probably by the named artist but is less certain than when it uses the artist's name alone. "Studio of", "Circle of", "Follower of" and "After" claim progressively less; each house defines the terms in its catalogue glossary.
How much is the buyer's premium at Sotheby's?
Sotheby's Help Centre lists 28% up to $2 million in New York (£1.5 million in London), 22% up to $8 million (£6 million), and 15% above, excluding local taxes. Wine and spirits are 24% plus a 1% overhead premium.
How do I work out my maximum bid?
Divide your all-in budget by one plus the premium rate. With €100,000 to spend and a 28% premium, the maximum hammer is €78,125, before taxes and shipping.
Is the condition report a guarantee?
No. It is prepared on request and is usually stated not to be a warranty in the conditions of sale. For a significant lot, inspect in person or commission an independent report.
What does "estimate on request" mean?
It appears on top lots where the house does not print a public estimate; ask the specialist for guidance before registering to bid.
