What "genuine" means
It does not mean "expensive" and it does not mean "unique". It means the work is what the seller says it is: made by that person, in that technique, in that number of copies. A work costing a few tens of euros can be perfectly genuine; one costing thousands may not be.
The signature
Look at where and how it is signed.
- An art photograph is usually signed in pencil, on the front in the white margin or on the back. Pencil is a technical choice: it does not bleed through the paper and does not degrade the way many inks do.
- A signature printed with the image is not a signature: it is part of the reproduction. You can tell because it is at the same resolution as the image, with no relief and no variation in pressure.
- On a painted work, the signature is in the material of the work itself.
The certificate
A certificate of authenticity is useful if it carries verifiable information: title, year, technique, exact dimensions, edition number if any, and the signature of whoever issues it. A sheet saying only "original work" with a stamp adds nothing and proves nothing.
The strongest certificate is issued by the artist, or by the gallery representing the artist. One issued by a third party with no relationship to the author is worth exactly that third party's reputation.
Provenance
This is the chain of who has owned the work. For a contemporary piece bought from whoever makes or represents it, provenance is short and simple: it is the receipt. Keep it with the certificate — over time it becomes the most useful part of the file.
The signals that should give you pause
- No precise answer about the printing technique or the support.
- An edition size stated verbally but not written on the work.
- "Limited edition" with no number.
- A price far below market, with urgency attached.
- Photos of the front only, never the back, never a detail.
None of these alone proves fraud. Together they say there is no professional on the other side, which is reason enough not to buy.
What to ask, in practice
Ask for a photo of the back and a close-up of the signature. Two normal requests that any serious seller satisfies in five minutes, and that settle the question in most cases.