Expertise · Science · History of art
Authenticate a Leonardo da Vinci
No machine answers "yes" or "no". A solid attribution arises from the convergence between archives, material history, scientific imagery, technique, style and knowledge of the workshop.
The short answer
To authenticate is to construct a body of evidence
An old panel, compatible pigments and a beautiful sfumato are not enough. A 16th century copy can combine these three qualities. Expertise requires that independent clues converge and contradictions be explained.
Autograph
Execution attributed mainly to Leonardo with strong scientific consensus.
Leonardo and workshop
Design or interventions by the master, shared or difficult to separate achievement.
Workshop/follower
Close work, sometimes supervised, but without a demonstrated autograph hand.
Contested attribution
Serious arguments and persistent objections; the cartel can evolve.
I · The chain of expertise
Seven questions in the correct order
A commercial certificate is not a consensus
A private opinion can be helpful, but assigning a Leonardo ideally requires a published record, reproducible reviews, access from multiple specialists to the work, and adversarial discussion.
II · What science sees
The exams answer specific questions
| Method | What she reveals | Which she doesn't prove alone |
|---|---|---|
| Dendrochronology/study of wood | Gasoline, construction, possible age and panel transformations. | That Leonardo painted on it: old wood can be reused. |
| Infrared reflectography | Carbon design, hatching, transfers, repentances and abandoned compositions. | That the route is by Leonardo's hand rather than a collaborator. |
| X-ray | Structure, certain pigments, nails, assemblies and profound modifications. | An automatic stylistic signature. |
| Uv fluorescence | Varnishes, repaintings and restoration interventions. | The complete original condition when the surface is heavily altered. |
| Chemical analyses | Pigments, fillers, binders and local order of layers. | An attribution if materials are common in the workshop. |
| Hyperspectral imaging | Subsurface information and material mapping. | A verdict without historical and technical interpretation. |
III · The workshop trap
A copy can follow Leonardo correction after correction
Case study · Madrid
The Prado Mona Lisa
Restoration and examinations of the Prado revealed the landscape hidden under black repaint. The underlying drawing and several corrections follow the process of the Louvre original, indicating a parallel execution in the workshop.
However, the painting remains attributed to an unidentified author from the workshop. It is the perfect demonstration that extraordinary technical proximity does not automatically transform a supervised copy into an autograph work.
See reproduction
Shared case · London
The Virgin of the Rocks
The imagery reveals a first composition abandoned under the painting. But the visible execution is not necessarily uniform: distinguishing invention, underdrawing, autograph passages and workshop participation requires reading zone by zone.
See reproductionIV · Four files
From consensus to controversy
Strong consensus
Ginevra de' Benci
Ancient provenance, stylistic coherence, support, technique and scientific documentation converge. Its attribution was however forgotten in the 18th century, when it was cataloged as a Cranach: the history of a name can be lost and then reconstructed.
See reproduction
Attribution debated
Salvator Mundi
Quality of certain passages, repentance and technique support an intervention by Leonardo for several specialists. Material condition, restorations, workshop participation and uneven quality fuel objections. The exact degree of autography is not the subject of universal consensus.
Cautious wording: "attributed to Leonard" or "Leonard and workshop" depending on the source cited, and not final verdict.
See reproduction
Unfinished work
Saint Jerome
Incompletion helps the expert: drawing, setting up, modeling and more advanced passages coexist. The imprints, repentances and continuity between anatomical thinking and execution provide access to the process rather than just the finished surface.
Restore without reallocating
Saint Anne
A restoration can clarify the original layer and allow for new comparisons, but it does not create an attribution on its own. Conservation, technique and art history must remain articulated.
See reproductionV · Style
Recognize a way without falling into imitation
| Hint | Leonard's | Why he can deceive |
|---|---|---|
| Sfumato | Gradual transitions integrated into the modeling and atmosphere. | Students and restaurateurs may imitate or exaggerate it. |
| Hands | Anatomy, narrative gesture and continuity of joints. | A nice hand can come from a workshop specialist. |
| Smile | Mobile expression constructed by peripheral shadows. | The "leonardesque smile" becomes a formula among followers. |
| Landscape | Coherent geology, water and atmospheric perspective. | The patterns circulate in boxes and copies. |
| Repentances | Transformations revealing a thought in progress. | Repentance proves a creation, not necessarily the specific author. |
VI · Art market
Seven warning signs before any expertise
"Guaranteed signature"
Leonardo's works are not authenticated by an isolated signature.
Family secret
An oral account without dated documents is not a provenance.
Photo only
No layers, supports, restorations or surfaces are judged from a JPEG.
Only one laboratory
A compatible pigment gives a possible date, not an author.
Anonymous expert
An unverifiable and unpublished opinion does not create consensus.
Commercial emergency
The pressure to buy before adversarial examination is a red flag.
Price as proof
A spectacular estimate does not strengthen the scientific record.
What to do if you think you own a Leonard?
Do not clean, restore or take anything. Document the reverse, frame, labels and any family archives; contact a qualified conservator-restorer, a specialist historian and, if necessary, a heritage laboratory. Legal advice on ownership and provenance may be essential.
Institutional sources
Technical files and workshop practices
Continue
Workshop, works and debates
FAQs
Attribution issues
Is there a single official Leonardo expert?
No. The responsibilities are based on specialists, institutions, publications and examinations whose conclusions may differ.
Can we authenticate a painting with pigments?
Pigments can exclude a date or confirm compatibility, but do not prove Leonardo's hand alone.
Is a fingerprint enough?
No. Its quality, its origin, contaminations and the absence of a certain biometric base prevent a simple verdict.
What is a work "by Leonardo and workshop"?
A work whose conception or certain passages are linked to the master, but whose execution includes collaborative participation.
Why do attributions change?
New restorations, imaging, documents, comparisons and reassessment of workshop operation modify the file.
Is Salvator Mundi authentic?
Several specialists defend an intervention by Leonardo; others reduce its role. The degree of autography remains debated.
0 comments