Case Study: Detecting a Forged Alberto Giacometti Signature

Signature Attributed to Alberto Giacometti

This case study illustrates the purpose of our First Expert Opinion service by presenting an example of a preliminary signature assessment conducted prior to the potential acquisition of an artwork attributed to Alberto Giacometti.

Scope of This Case Study

This case study is based on an actual mandate received by the International Autograph Authentication Board from a private collector who requested a first expert opinion regarding the authenticity of a signature prior to the potential acquisition of an artwork attributed to Alberto Giacometti.

The client granted permission for this case to be presented as an educational example illustrating the type of initial analysis that may be conducted when collectors seek a first professional opinion before acquiring an item.

For confidentiality and educational purposes, several limitations have been applied in the present illustration:

The signatures presented in this case study have been intentionally reduced in image quality.
Only four comparison signatures (C1–C4) are presented for illustrative purposes.

In actual authentication work, our analysis typically relies on a broader reference set of approximately 8 to 15 verified signatures, depending on the availability of material and the historical period under consideration.

A preliminary signature assessment focuses on identifying distinctive graphic characteristics that may either support or contradict the hypothesis of common authorship. Experts pay particular attention to elements such as:

stroke construction
movement dynamics
letter formation
terminal strokes
overall writing rhythm

When significant discrepancies are observed in these fundamental characteristics, the expert may issue an initial opinion advising caution regarding the acquisition of the object.

It is important to emphasize that this type of assessment represents a first-level expert opinion based primarily on visual handwriting analysis. It does not constitute a final authentication. A full authentication would normally require a more comprehensive examination including the artwork itself, its support, medium, provenance, and other forensic considerations.

The following illustration presents the questioned signature (Q1) alongside four comparison signatures (C1–C4) used for this educational analysis.

Examination

To evaluate the similarities and differences between the questioned signature and the reference examples, several structural elements of the handwriting were examined in detail.

The comparative analysis focuses on three distinctive features visible in the enlarged illustration below:

the construction of the letter “T” in Alberto
the structure of the capital “G” in Giacometti
the terminal stroke of the final “i”

These elements are particularly informative because they reflect the writer’s habitual stroke construction and movement dynamics. Such characteristics tend to remain relatively stable within an individual's signature, even when natural variations occur.

Construction of the “T” in Alberto

In the comparison signatures (C1–C4), the letter T is consistently formed using two distinct strokes, creating a clearly defined cross structure.

The vertical stroke appears to be executed first, followed by a rapid horizontal bar projected outward. This produces a tense and dynamic appearance, often resembling an arrow-like movement.

In the questioned signature (Q1), however, the T is formed in a single continuous movement. The stroke rises along the vertical axis before descending and extending outward to form the horizontal bar.

This construction results in a softer cursive form, differing from the more segmented and energetic cross structure observed in the comparison signatures.

Structure of the Capital “G” in Giacometti

In the reference signatures, the capital G is highly simplified and appears less as a defined letterform than as a fluid descending movement.

The stroke flows smoothly into the following letters with continuous curvature and no abrupt directional changes, reflecting a rapid and natural writing motion.

In the questioned signature, the central portion of the G shows a sharp angular return, creating an abrupt return in the stroke where the line almost folds back on itself.

This angular construction interrupts the otherwise fluid movement and differs from the consistently undulating and continuous stroke observed in the comparison signatures.

Terminal Stroke of the Final “i”

The terminal stroke of the signature provides additional insight into the writer’s movement dynamics and finishing gesture.

In the comparison signatures (C1–C4), the final stroke consistently shows a decisive downward movement, executed with a confident and energetic finish. The trajectory of the stroke presents a convex curvature, indicating a natural continuation of the writing motion as the pen exits the signature. These strokes typically end with a firm descending line, reflecting a controlled and assured termination of the signature.

In the questioned signature (Q1), the terminal stroke differs in several respects. The stroke begins with a concave trajectory, in contrast to the convex curvature observed in the comparison signatures. Additionally, rather than continuing downward, the stroke changes direction and ends with a small upward hook extending toward the right.

This upward terminal hook contrasts with the strong descending finishing strokes observed in all comparison signatures, which display a more decisive and confident exit movement.

The differences observed in both the curvature and the final direction of the stroke indicate a variation in the natural termination pattern of the signature.

Preliminary Opinion

The observations presented above represent only a portion of the analytical process normally undertaken during a full authentication examination. In professional practice, a comprehensive assessment would typically include a broader corpus of comparison signatures, as well as the direct examination of the artwork, its support, medium, provenance, and other relevant forensic considerations.

However, the elements highlighted in this case study — particularly the construction of the letter “T” in Alberto, the structure of the capital “G” in Giacometti, and the terminal stroke of the final “i” — are considered structurally significant handwriting characteristics. These features reflect the natural writing mechanics and movement patterns of the signer and therefore tend to remain relatively stable across authentic signatures.

In the present case, the questioned signature displays several discrepancies in stroke construction, movement dynamics, and terminal stroke direction when compared with the reference signatures examined.

While these observations represent only part of the overall analytical framework, they constitute highly significant indicators in handwriting comparison and can provide meaningful insight during a preliminary evaluation.

Based on the differences observed in these key structural elements, the questioned signature appears unlikely to have been produced by the same hand as the reference signatures.

At this preliminary stage, our professional opinion would therefore be unfavorable to authenticity, with an estimated probability of approximately 70–80% that the signature is not genuine, pending a complete forensic authentication examination.

Professional notice:

This case study illustrates the type of preliminary advisory assessment that may be provided to collectors prior to an acquisition. Such opinions are intended to assist in risk evaluation and should not be considered a definitive authentication without a full examination of the original object.