The artist matters most
Before anything else, value follows the name. A work by a listed artist with a track record at auction can be worth many times a technically finer painting by an unknown hand. The record makes the point: Leonardo's Salvator Mundi sold for $450.3 million at Christie's in 2017 — the most expensive painting ever at auction — largely on the strength of its attribution.
So the first question is not “is it good?” but “who made it, and does the market know them?” Everything below either supports or qualifies that answer.
Original or reproduction?
A great many “paintings” are prints. Under a 10× loupe, a printed reproduction reveals a regular pattern of tiny dots (a rosette); an original shows continuous, irregular brushwork.
Look and feel for raised paint, texture and impasto. A perfectly flat, glassy surface — especially one glued to board — usually signals a print, which is worth a fraction of an original.
Signature and inscriptions
A signature can confirm an artist, but it can also be added later or faked, so it is a clue rather than proof. Note its placement, spelling and how it sits within the paint.
Monograms, dates and titles — on the front or the reverse — all help place a work and its maker.
Provenance and documentation
Provenance is the chain of ownership — receipts, gallery labels, exhibition history, catalogue references. A clean, continuous history lifts both confidence and value; gaps invite scrutiny.
The back of a painting often tells more than the front: labels, stamps and inventory numbers are quiet corroboration.
Condition, medium and format
Condition moves the figure hard. Tears, flaking, heavy restoration and overpaint all discount a work; sympathetic, documented conservation is expected.
Medium and support matter too — an oil on canvas generally outranks a work on paper — as do size, subject, and where the piece sits within the artist's career.
- Read the surface under raking light for repairs and overpaint.
- Original oil on canvas outranks a print or a study on paper.
- Desirable subjects and mature-period works command more.
When to seek a considered opinion
If the signs point somewhere interesting, resist the urge to clean or restore — that can destroy value — and get an informed reading first. Our Painting Value Indicator gives a rough orientation from medium, size, condition and the artist's standing.
For a real figure, a documented record brings detailed captures, an AI-assisted reading of hand and period, and comparable sales together. Any such figure is an informed opinion, not a valuation or guarantee.