How to value a painting

Valuing a painting means answering four questions in a fixed order. Who made it, what have comparable works by that person sold for, what condition is this one in, and who wants it at the moment. Skip the first question and everything after it is arithmetic on a fantasy. Most disappointing valuations come from an owner who started at question two with a name that was never established.

Attribution sits on a scale rather than a switch. A signed work with a documented chain of ownership back to the studio sits at one end. A work catalogued as circle of, follower of or attributed to sits at various points below, and each step down cuts the price by a large factor. Auction houses use that vocabulary precisely, and learning to read it is the fastest way to understand a low estimate that looks insulting.

Comparable sales are the backbone

A comparable is a work by the same artist, of similar size, from a similar period, in similar condition, sold recently in a public market. The closer the match, the more weight it carries. One sale proves nothing, three or four clustered around the same figure describe a real price. Databases of auction results are the standard source, and they cover the hammer price plus buyer premium, which is the number a buyer actually paid.

Private sales are invisible to those databases and they run higher than auction, sometimes considerably. That gap explains why a gallery price and an auction estimate for the same artist can look like figures from two different markets. Both are true. Auction is a wholesale environment with a clock attached, and the retail level carries the cost of a room, a staff and the time it takes to find the right buyer.

Condition moves prices more than owners want to believe. Relining, extensive overpaint, a tear through the primary image area, sun bleaching in a passage of red, all of these cut into the number, and the cut is deeper for a well documented artist because buyers have alternatives. A condition report from a conservator costs a few hundred and it is the cheapest step in the whole process. Ask for one before you set expectations.

1. Establish the attribution first and write down which level of certainty it actually sits at
2. Find three or four sold comparables by the same artist at similar size and date
3. Adjust for condition using a conservator report rather than your own reading of the surface
4. Adjust for provenance, exhibition history and any published references to the work
5. Separate the retail replacement figure from the likely auction figure and never quote one for the other
6. Get a written appraisal from a qualified appraiser if the number matters for insurance or tax

The last line is not a formality. Insurance valuations, estate valuations and market valuations answer different questions and produce different numbers for the same object. An insurer wants the cost of replacing the work at retail. An executor wants what it would fetch in an orderly sale. Quoting one figure where the other is required causes arguments that are expensive to settle later.

Where amateurs go wrong

Two errors account for most bad home valuations. The first is treating asking prices as evidence, when an unsold listing at a high number proves only that nobody paid it. The second is valuing the subject rather than the artist, since a charming picture of a harbour by a minor painter stays a minor painting no matter how much you like the harbour. Both errors point the same direction, upward.

An asking price is an opinion. A sold price is a fact. Value the work on facts and treat every opinion in the room, including your own, as a hypothesis.

For contemporary work by living artists with a thin auction record, the method changes slightly. You work from the gallery price list, the size ladder the artist uses and the pace at which their shows sell out, since those are the only public facts available. The logic stays the same even when the evidence is thinner.