Fine art authentication is a process that ensures the integrity of artworks, preserves cultural heritage, and maintains trust in the art market. By combining traditional methods, scientific advancements,^[1][2] and emerging AI^[3] and Blockchain technologies,^[4] art authentication can offer accurate attributions and protect the artistic legacy for future generations.^[5] It consists of proving the authenticity of an artwork and its attribution to a specific artist.^[6] This process involves determining the origin, authorship, and historical significance of a piece of art.^[7] The proliferation of art forgeries and the increased skill of the forgers who are aware of what scientific analysis reveals requires a rigorous approach to fine art authentication.^[8][9]

The requirement for art authentication has been a historical practice, evolving over centuries alongside the growing recognition of artists and the increasing value associated with their creations. During the Renaissance,^[10] the authentication of artworks was primarily based on the artist's style, brushstrokes, and technical mastery. Nevertheless, distinguishing between the original and the copy often proved challenging.^[11] As art markets expanded globally and new artistic movements emerged, the authentication process became more intricate.^[12]

Documentation examination involves scrutinizing the authenticity and accuracy of supporting paperwork, including certificates of authenticity, exhibition, and gallery records, as well as correspondence.^[13]

Art authentication is a complex and multifaceted process, often accompanied by challenges and controversies. Some of the key issues include:^[11][14]

Thierry Lenain^[15] asserts that a forger's goal is to mislead the public into believing that the generated work of art is something else entirely.^[16]

Throughout the 20th century, scientific methodologies were integrated into art authentication, resulting in significant advancements. Experts were able to examine artwork beyond their surface layers with the use of techniques such as radiography, infrared imaging, and ultraviolet analysis.^[17][18] In the 21st century, the field of art authentication has progressed significantly due to digital imaging, computer-based analysis and Artificial Intelligence (AI) integration. These technological advancements have enabled new possibilities for obtaining insights into the pigments, materials and features of artwork. Computer analysis, powered by AI algorithms and data-driven assessments, compares works of art to extensive databases, facilitating pattern-based learning.^[18]

Authentication of artworks is a meticulous process that requires a multifaceted approach, resourcing to traditional art historical methods as well as to the precision of scientific inquiry.

Authentication techniques are instrumental to this field, encompassing a wide array of methods including provenance research, stylistic examination, the scrutiny of historical documentation, and assessments by subject-matter experts. Moreover, the advent of cutting-edge scientific methods and the application of Artificial Intelligence have considerably broadened the scope of art authentication.

For instance, discerning the pigments utilized by an artist can unveil aspects of their methodological practices, thereby situating their work within a broader art historical narrative. This synthesis of art history and technology not only fortifies the authentication process but also deepens our comprehension of the artwork within its historical milieu.

Provenance Research: Provenance, or the documented history of an artwork's ownership, is a very important aspect of authentication, examining its lineage from creation to the present day.^[7] Scholars and experts trace the ownership trail of a piece, examining catalogs, exhibition records, receipts, correspondence, and any other relevant documents to establish its authenticity.^[19]

Stylistic Analysis: Art historians and connoisseurs analyze an artwork's style, composition, technique, and subject matter to attribute it to a specific artist or artistic movement. This approach relies on in-depth knowledge of art history and the ability to discern subtle nuances and distinctive characteristics.

Scientific Techniques - Imaging Techniques: Scientific techniques such as material testing laboratories include instruments that allow for determining aspects such as elemental and molecular composition, undertaking particle characterization, and identifying the organic phases present in a work of art. As an example, particle analysis, also known as pigment analysis, allows knowing where, when, and how a painting was created by enlarging and understanding the specific materials in a painting.

Ultra-high-resolution digital images at multiple wavelengths, including ultraviolet fluorescence (UV), visible, infrared (IR), and X-rays and other imaging methods reveal hidden layers, underdrawings, pentimenti, and alterations.^[20] The three-dimensional surface of paintings can be captured with a 3D scanner, to reveal working practices and conditions.

Radiocarbon dating, also known as carbon-14 dating, is a scientific method that can accurately determine the age of organic materials up to about 60,000 years old. This technique, first developed by Willard Libby in Chicago in the late 1940s, is based on the decay of the carbon-14 isotope. Radiocarbon dating led to the “radiocarbon revolution” in archaeology and it has been useful also in the domain of art history.^[21]

Materials Analysis: Non-invasive or minimally invasive sampling techniques, such as X-ray fluorescence (XRF), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), radiocarbon dating^[2] and pigment analysis^[22] help identify the pigments, binders, varnishes, and other materials used by the artist. This information provides insight into the age of organic materials and alterations of the artwork.^[23]

Documentation and Expert Opinions: Documentation examination involves scrutinizing the authenticity and accuracy of supporting paperwork, including certificates of authenticity, exhibition, and gallery records, as well as correspondence.^[13] Art authentication also relies on the expertise and opinions of specialists, scholars, curators, and artists familiar with a particular artist or artistic style. Their insights, along with supporting documents, scholarly publications, and catalog raisonnés, contribute to the overall evaluation of an artwork’s authenticity.^[24]

Artificial Intelligence: Digital technologies have enabled the analysis of intricated details such as brushstrokes, color palettes, and stylistic elements unique to individual artists. AI systems can identify patterns in vast amounts of data. This capability enables experts to detect potential forgeries and differentiate genuine artworks from imitations. AI algorithms can process and interpret diverse data sets, facilitating a data-driven approach.^[3][25] A company that offers AI art authentication services is Art Recognition.

Blockchain technology, known for its decentralized and immutable characteristics, facilitates the establishment of secure digital records that track an artwork's provenance and history. On the art market specifically, “blockchain can counteract the lack of documentation and the burden of proving ownership”.^[4]

Art authentication is a complex and multifaceted process, often accompanied by challenges and controversies. Some of the key issues include:^[14]

Subjectivity and Interpretation: Art authentication is inherently subjective, relying on the individual expertise of scholars and specialists and varied interpretations.

A prominent example highlighting this issue is the debate surrounding the Salvator Mundi, attributed to Leonardo da Vinci.^[26] This painting has become a focal point for discussions on attribution, with some experts contesting its provenance and others defending it. Such examples accentuate the varying perspectives and the sometimes polarizing nature of art attribution.^[27]

Forgery: The art world has witnessed numerous cases of skilled forgers who replicate famous artworks with precision. Moreover, forgers now can employ generative AI to produce imitations that mimic the style of a particular artist.^[28] However, a study has shown that AI technology can detect digital forgeries produced by a generative AI, if AI-generated imitations are fed into the training.^[29]

Lack of Standardization: There is not a universally accepted standard or governing body for art authentication. The art world, of course, is an unaffiliated consortium of art historians, curators, merchants of varying stripes.^[30] This lack of standardization can result in disparities in authentication practices and varying levels of confidence in attributions.^[31]

Legal and Ethical Considerations: Authenticating an artwork can have legal and financial implications. Authentication can influence an artwork's value, ownership disputes, and copyright issues. Balancing the interests of artists, collectors, scholars, and the art market while maintaining transparency and fairness is a complex ethical challenge. Lawsuits against the authenticator who dashed their hopes are common.^[31]

Restoration: Restoration involves any attempts made to repair or conserve a painting by altering its original surface with later additions. When a painting undergoes restoration, it can pose challenges for its authentication. The restoration process may modify or obscure the original elements of the artwork, making it difficult to determine its authenticity accurately.

Training images in AI-based authentication methods: Training datasets are preeminent for the success of AI training as well as the AI assessment of an artwork’s authenticity. Acquiring a diverse and comprehensive collection of high-quality training images can be difficult. Insufficient or limited training data can result in the AI model lacking the necessary knowledge to make accurate authenticity assessments.