Intention and deception

With reference to the art world, a fake is usually considered to be an object made with the intention of creating deception as to the author and period of production, this intent is confirmed by offering the work on the market.

In order to define a work of art as fake, it is necessary, even from a legal point of view, the evidence of fraud; but it is precisely in this aspect that the difficulty of declaring falsehood is evident, in fact, “The fake is not a fake until it is recognized as such, since falsehood cannot be considered as an inherent property of the subject” [1]; In fact, Brandi argues that “falsehood can only be based on judgment. The difficulty of the definition must be traced back to the complex problem inherent in the phenomenon that presents relationships with others of copying, replication, imitation, the differentiation of which does not lie in a specific diversity of production methods, but in a different intentionality “.

From this we can derive the legal formulation of the concept of fake, since, as it is universally known, the artistic forgery falls within the order of crimes to the extent that it deceives the good faith of the buyer, damages the rights of the author and his public, in short, as a commodified product, it assumes an abusive reality and characteristics that do not belong to it.

Forgery as a cultural factor

Artistic falsification is not simply identified with commercial fraud, in reality it is, first of all, a cultural fact as it always arises from a precise cultural context and is produced to satisfy needs that are primarily of culture.

As Carlo Ludovico Ragghianti notes, counterfeiting activities are more complex than what is usually thought, with in some cases “the presence of processes that extend towards higher intellectual forms such as formal understanding, interpretation, criticism itself”. Obviously, one cannot falsify Donatello without knowing him, and since knowing him means reading him, interpreting him, according to the critical angle that varies over time with the variation of historical and cultural conditioning, here is that a false Donatello will also be, of necessity, a critical interpretation of the Tuscan sculptor, an eloquent document of culture. And it will still be questionable why the forger on that occasion tried to imitate Donatello’s style and not, say, that of Jacopo Della Quercia or Lorenzo Bernini.

Bust of Savonarola, forgery from the Florentine Fifteenth Century style, a sort of romantic sublimation of the prophet with his gaze turned to the sky

That is a legitimate question because the forgery, like any other human artefact, is conditioned by the economic law of demand, it always presupposes the target audience, its tastes, preferences, the average degree of critical maturity and cultural inclination of the likely buyers.

In this aspect, the fake holds a “historical-critical” value, identifying in it the way in which, at different times, one approaches the reading and interpretation of other eras.

Intermediate manifestations and hybrid forms

It is precisely in this arrangement that the possibility of recognizing the real nature of the fake can be found: according to Otto Kurz [3] the fakes “are a kind of abbreviation that translates the work of art into a contemporary language”. The complexity of the phenomenon is linked to what Frank Arnau [4] defines “intermediate manifestations”, “hybrid forms”, the various and badly definable category of imitations, partial originals, originals built on other originals; Arnau wonders “where does the copyist’s work end and where does that of the forger begin”. In this regard, Otto Kurz’s following observation is interesting: “from a moral and legal point of view, falsifications form a separate category, but otherwise they have much in common with reproductions and copies, as they come close to the originals, without ever reaching them “.

In fact, however different the purpose of those who make a copy for documentation and those who follow them to smuggle it as an original may be, in both cases the performer will never be able to free himself from the cultural conditioning of the time in which he lives. ”Each time has different eyes. Donatello in 1930 did differently from how it appeared in 1870. “The imitable element appears different to each generation” so Friedlànder, in his famous essay [5], addresses the problem. The copier and the forger will then want to preserve in their reproduction that typical particularly valuable aspect, and will inevitably overlook the rest; from this it follows that even the copies have a date and reveal that they belong to a historical period.

Therefore the copy, the imitation and the fake reflect the cultural aspect of the moment in which they were performed, they enjoy a historicity that could be said to be double, due to the fact that they were made in a specific time and to the fact that they itself, inadvertently, carry the testimony of the preferences and the taste for fashion of that time. Brandi argues, the history of the falsification of works of art is part of the history of art criticism, as the forgery can reflect the particular way of “reading” a work of art and of inferring the style that was typical of a given historical period.

In conclusion, the history of falsification must equally take into account copies and imitations not only for the substantial identity of the procedures used, but also for the difficulty of proving fraud (essential for the judgment of the forgery) and for the impossibility of excluding ( even in the most remote periods of civilization) an intentional production of fakes.

Counterfeiting and imitation

The contributions coming from a historical investigation that takes into account its formation as well as some facts in its development can be useful and sometimes decisive in its aspects for a more exact evaluation of the forgery.
In confirmation of some previous considerations, it should be noted that the falsification, and therefore a possible history of it, is subsequent to the “formation of a critical and valuable judgment … Almost like a negative corollary of it” [6]. And this because in it, beyond any motivation, it is always identifiable a more or less conscious “critical” operation with regard to the originals that are intended to be reproduced. In this respect, some episodes are of particular interest and exemplary: that of Michelangelo who painted a marble Cupid and after having buried it “he arranged it in a way that seemed ancient” [7]; but it is significant that Vasari himself judges Cardinal San Giorgio’s blame to be inappropriate, “who, not knowing the virtue of the work, which consists in perfection, which are as good as the ancient ones provided they are excellent, being there more vanity in those who follow the name rather than the ‘facts’. From where the recognition of an intrinsic value of the work is obtained, a value which can obviously be identified to different degrees in each fake and which constitutes another and not negligible element to which reference must be made. We will still remember Lorenzo Ghiberti who forged Greek and Roman medals and other artists who signed gems carved with the name of Philaretes, Pyrgoteles, Leukos in Greek letters [8]. Of course, their purpose was not to mystify the ancient (if not for fun or ambition), but to get close to it, identifying with its artistic manifestations and recreating its style; therefore, we cannot speak of falsification since there was no malicious intention, but rather of counterfeiting [9].
Later, between the end of the Sixteenth and the beginning of the Seventeenth Century, when artistic historiography has usually institutionalized the divine fame of certain artists and the Renaissance age begins to be revised in terms of celebratory rhetoric, the great masters of the sixteenth century will mostly be the ones to be falsified.

First authentications

During the Seventeenth Century, parallel to the consolidation of the concept of artistic property, as well as collecting and the art market, we witness the spread of the phenomenon. The production of fakes takes on modern characteristics in the sense that it adapts to the demands of collecting, scrupulously respects the preferences of the intellectual classes to which it is intended, and becomes the immediate proof of every important critique and market success.

In his Liber Veritatis – one of the index pages is pictured in the image – Lorain traced, with a succinct drawing, the memory of his paintings, in order to guarantee himself and guarantee the patrons from falsifications.

To remedy the illicit reproduction of their works (legally protected by copyright laws for the first time in England in 1735) the artists of the Seventeenth Century, who were the most damaged by the imitators, compiled detailed lists, often accompanied by drawings, of their paintings. Claude Lorrain, in order to safeguard the good name and the rights of his public, compiles the “Liber veritatis”, which is a methodical and scrupulous documentation of all his work. this is the first example in the history of art of authenticating one’s work done by a living master.

Since then, for the first time, the definition of “falsifier” replaced that of “imitator”. This type of forgery testifies to the poor living conditions of the apprentices and of the unsuccessful painters who traded in their products.

The fake in the Eighteenth Century

Starting from the Eighteenth Century, the production of fakes respects so closely the characteristics of the new aesthetics and the tastes of an increasingly specialized public, that we could ideally reconstruct the progress, the enthusiasm, the myths of the last two hundred years from the most significant artistic counterfeits. The forger who in the ‘500 and ‘600 still worked with relative freedom and approximation is now forced to deal with an increasingly rigorous criticism and must promptly record in his work the changing evolution of taste. If on the one hand the forgery becomes more cunning and from the technical point of view more convincing, on the other hand it denounces, with ever greater precision, the historical and cultural implications that produced it.

Anton Raphael Mengs, Jupiter kissing Ganymede, a fake Pompeian fresco created to deceive the archaeologist and art historian Johann Joachim Winckelmann, who considered it an original. In 1779, on his deathbed, Mengs himself confessed that the famous Ganymede was his doing

In the second half of the 18th Century, in an atmosphere of archaeological fervor prompted by Pompeian excavations and by Winckelmann’s aesthetic theories, some workshops such as that of Giuseppe Guerra specialized in the falsification of classical painting. In those years Winckelmann himself was deceived by the “Jupiter kissing Ganymede”, painted in encaustic by Raphael Mengs so much that he had it engraved for his “History of the Arts of Drawing among the Ancients”. In 1786 when the news of the origin of the painting was leaked, Goethe, admired and incredulous, wondered in his “Italialienische Reise“ how could a painting “which is almost too beautiful even for Raffaello” be the work of a modern artist. Goethe’s comment is extremely significant, in fact Mengs’s painting is much closer to Raffaello’s ways than it is to those of Pompeian frescoes, nor could it be otherwise in an era in which the concept of “classicism” was identified with that of “ideal beauty” and recognized in Raffaello’s art the unmatched peak of formal perfection. On the other hand, Winckelmann’s error and Goethe’s enthusiasm can be explained by the fact that both in those years saw classical antiquity with the same eyes as Raphael Mengs and its falsification was therefore nothing else, on closer inspection, than an interpretation of the ancient perfectly adequate to the ideas of the intellectual environment for which it was made.

A fake Memling is the first pleasant Memling

The essential characteristic of any truly successful falsification is in fact that of adhering so intimately to the judgments or prejudices of the public to whom it is intended, to be sometimes valued as much more beautiful than an authentic work at first sight.
It goes without saying, of course, that we are dealing with an immediate emotion, an entirely superficial sympathy that a cold and detached analysis can later rectify; it is also true however, as Friedlander notes with irony, that “for many amateurs, a fake Memling is the first pleasant Memling”. This explains how illustrious connoisseurs have been deceived in the face of falsifications that make us smile today and how sensational fakes have entered the art collections and the pages of specialized magazines with full honors.

The Nineteenth Century- Bastianini and Dossena

Giovanni Bastianini (1830-1868) The Dance. A plaster version of this group can be found in the Galleria d’Arte Moderna, Palazzo Pitti, Florence

In the Nineteenth and Twentieth Centuries(in which the problem becomes pathological) the mythical personality of the forger was born: Giovanni Bastianini in the mid-Nineteenth Century reruns the Renaissance, Alceo Dossena at the beginning of the century measures himself with the art of all times, Hans Van Meegeren causes the famous Vermeer scandal. None were as able as they were to look at the world of art with the same eyes as the educated public to whom their works were destined; offering critics and collectors the Pisanos, Donatellos and Vermeers whom they would have liked to meet.

It is curious that scholars, easily deceived by ancient falsehoods, sometimes rejected new discoveries that did not fit into that codified image of ancient art that had been taking shape.

Bastianini, in his famous terracotta imitations, offers us an interpretation of the Tuscan Renaissance which, situated between romantic and realist, though having very few points of contact with the models he tries to fake, fits perfectly nevertheless into the rather oleographic idea that the Nineteenth-Century literature made of the Italian Renaissance.

Alceo Dossena (1878-1937), Madonna and child, 1930.
His works were made in the style and technique of the great masters of the past.

The personality of Alceo Dossena was singular in the history of falsification. Born in Cremona in 1878, Dossena was a sculptor who practiced the various ancient techniques, not by imitating but by drawing inspiration in his creations from Greek, Etruscan, Roman and Renaissance works. Due to the quality of the style and the very nature of the patina that covered it, Dossena’s works left more than one archaeologist perplexed and sparked controversy, some not yet dormant.

The Twentieth Century- Hans Van Meegeren

In the Twentieth Century the work of art becomes a profitable investment as well as an element of social prestige. The dizzying increase in demand for paintings and other antiques consequently increases the market for art counterfeiters, who increasingly refine their works and, thanks to modern technology, can imitate techniques, materials and colors of the various eras almost perfectly as well as exhibiting equally impeccable “certificates of authenticity”.

The case of Hans Van Meegeren deserves a special mention. Immediately before the Second World War, he painted the Disciples of Emmaus in the style of Vermeer that the most authoritative art critics welcomed as a wonderful masterpiece by the master of Delft. It was discovered only after Van Meegeren himself declared it was a fake.

Han van Meegeren (1889–1947), Supper at Emmaus, 1937; inspired by a Caravaggio painting and purchased in 1937 by the Boymans Museum in Rotterdam for an astronomical sum

The resounding success of Van Meegeren’s Vermeers is explained on the one hand by the cultural and mystical preparation of the forger who, appropriately adjusted on the meticulous analysis of Vermeer’s true works, ended up identifying himself with the way of thinking of the Vermeerian critique in vogue in those years. And then for the subtle intelligence of the forger who, having to remake Vermeer and, moreover, young Vermeer, aimed directly at Italy and on Caravaggio (the “Disciples of Emmaus” closely recalls the painting of a similar subject by Caravaggio) offering critics the clear proof they long sought of Vermeer’s Italian education.

What a wonderful chiaroscuro!

Anyone who is not an expert, but also not a novice, can experience the most immediate effect that an appropriate falsification compared to an original arouses, this is because the fake, as we have said, is more punctual in exhibiting the subject’s style and characteristics prescribed by the original. Sometimes the forger exaggerates: Otto Kurz describes some of these cases as the group of Van Gogh fakes that appeared on the market in the Thirties: among them there were four self-portraits and as many groups of tall flaming cypresses.

Therefore, falsification is also subject to the laws of likelihood already enunciated by Aristotle: the fiction engineered by man must be plausible to be credible, while in reality even improbable things can happen. This also reminds us of a very significant aspect of our way of enjoying paintings: with a blatant complacency that leads us to want to find in the painting what we used to think it should be.

In the introduction to his History of Art E.H. Gombrich describes this viewer as the one that “seeing a work of art does not abandon himself to it but prefers to look for the appropriate label in his mind. Perhaps he has heard that Rembrandt is famous for his chiaroscuro, and then seeing the Rembrandt, he nods knowingly and murmures: “What a wonderful chiaroscuro” and then moves on to the next painting [10].

Tampering

There is a type of artistic counterfeiting, however, the most subtle and the most dangerous of all, even if by rigor it does not fall within the order of typical fakes, which destroys or degrades or alters the original, causing damage to the artistic heritage that is often not repairable. These are tamperings made for profit on ancient works of art which are modified because the subject is considered unpleasant or poorly conformable.

Large baroque canvases are shredded and broken down to be sold in fragments; on paintings signed by minor masters, whose importance for the art historian can sometimes be decisive, the signature is carefully abraded, this because a casual expertise or the presence of complex style data can allow a more important attribution and therefore a higher commercial quotation.

The perfect fake

As for a forgery performed in our day, we must admit the possibility, albeit theoretical, of the “perfect” forgery, that is, perfectly adequate to the current level of knowledge and understanding of the values ​​of the original. The operation of the forger never goes that far, but the hypothesis of the “perfect fake” is useful to realize if there are tools, ideological or technical, that can surely detect it as such. From a technical point of view, it is evident that the forger’s difficulties decrease or increase in proportion to the antiquity of the piece to be imitated; in the sense that no, or almost, technical difficulty stands in the way of those who falsify the art of their time, while many and more and more serious ones arise as one recedes into the past. Nevertheless, the forgery of a contemporary work always reveals itself, in every time, as the least perfect version, due to the fact that it is the real understanding of the artistic quality of what one wants to falsify that requires an adequate historical “distance”. Failing this, the forger’s attention will naturally be drawn to more external and more easily recognizable characters than the original and therefore his work will betray the superficiality and approximation of his aesthetic approach.

It is also true that the knowledge of the deceived “consumer” will be equally limited, but the judgment of what the artist himself supposedly created can help him. This type of forgery, however, will not find credit for too long since, as we have said, the judgment on the values ​​of the original is clarified and circumscribed over time [11].

Adoration of the Magi, modern forgery in the style of the early Fifteenth Century in Florence. Collage of motifs borrowed from the famous polyptych by Gentile da Fabriano at the Uffizi

There is a close relationship between the work of the forger and that of the connoisseur: the two categories must work by playing to overcome each other, on an articulated, analytical knowledge, of the “package” of requirements that a certain type of original must possess.

The frauds

There are good fakes and rough fakes, but even when it is crude, the fake always says something, albeit negatively, about the competence of the public it manages to deceive: such as “De Chirico” sold as an original, thanks to the authentic mail on the back of the work (imitated to perfection with the slide technique projected on the canvas); or thanks to its description in pages inserted in qualified publications; or even archaeological pieces that are buried in excavated areas and then “brought to light” at night under the eyes of unwary buyers. In the latter case, the deception focuses more on the circumstances of the discovery than on the quality of the objects and, in the case of paintings with false authenticity, perhaps accompanied by an expert opinion, it is often on the presence of the latter that the deception relies on . These falsifications say something about the art market’s ways of deceiving; but the kind of forgery that can teach the art connoisseur is obviously not this, but the one in which the deception focuses on the quality of the artifact itself and not on accessory circumstances.

Chemical analysis

The prevention against fraud always stimulates the analysis of the originals through new techniques: but the falsifications keep up with the discoveries, and “the skill with which the forgery is executed becomes the natural law of defense of the author of it, proportional to the technical and archaeological knowledge of the target audience” [12]. Thus, increasingly convincing fakes are born that take into account new acquisitions.

Period of use of the blue pigments

Let’s take the chemical analysis for example: its usefulness is based, among other things, on the fact that it can reveal the presence of colors of modern invention in a supposedly ancient work.

Its introduction has therefore caused the decay, actual or potential, of all the fakes made with colors of modern production. A forgery by the Dutch painter Frans Hals (c. 1580 – 1666) which gave rise to a dispute taken eventually to legal seat at the beginning of the Century, was unmasked precisely by chemical analysis: this revealed the presence of three pigments that did not exist at all in Frans Hals’ era, namely synthetic ultramarine blue (produced for the first time in 1826), Thenard blue (cobalt oxide and alumina , invented by Thenard in 1820), and zinc white, which did not exist prior to 1781 [13]. Obviously, today’s forger is careful not to use pigments that can betray him during a potential chemical analysis.

The fight against forgery leads to the discovery of ever new characteristics of the originals.
The requisites of an ancient painting that the forger must try to procure for his work have now become numerous.

Support and ground preparation

Even just the support of an ancient painting has now been made the subject of a systematic observation that has recorded and made significant the most minute characteristics.

Here are some observations by Friedlànder on the supports of the paintings: “Usually the thickness of the wood, especially in the Dutch Seventeenth Century, was slightly rounded at the four corners on the reverse with a uniformly prismatic cut. The painters of the Fifteenth Century spread the preparation on the panel already framed: then the pasty mass formed a crust at the edge of the frame: if this crust is visible on all four sides, we can be sure that we have the painting in its original size.
We study the material as naturalists: the species of wood, the texture of the canvas and the pigments. With this we acquire points of reference to locate the painting in space and time. In the Netherlands and in northern Germany, oak was used exclusively, mostly of little thickness; in southern Germany usually lime or, especially in the Alpine area, the streaked wood of coniferous trees was employed; in Italy, poplar was usually used in rather thick boards “.

Superficial woodworm tunnels

A forger wishing to make a painting capable of deceiving a true connoisseur should take these and other requirements into account just to make the support. We understand how reproducing the whole set of requirements that are currently recognized in an original (now minutely analyzed by the work of generations of researchers) is a very onerous task and therefore constitutes a natural defense against falsifications.

One consequence is that the new forgery as a whole now occupies a more modest part in the forgery industry than ever; far more important are the manipulated and rigged materials, composed of modified ancient parts suitably worked in order to acquire greater value.
Common in the falsification of paintings is the use of an ancient support that automatically conveys in the finished fake a whole set of solidary characteristics typical of the authentic specimens, without however having the forger undertake procuring them one by one for the support.

Otto Kurz publishes useful observations on a false triptych executed on a modern fabrication medium. “The edges of the triptych… are harsh and uneven, and certainly such foul-grained pieces of wood would never have been used by an ancient master. The roughness of the central panel is due to a very visible cut through one of the figures. But irregularity is easily mistaken for antiquity and, in any case, the forger was above all anxious to use old wood. Yet it is precisely the wood that betrays him. The x-ray reveals that the woodworm holes were filled and then covered with primer. Of course, the painters of the Fifteenth Century had no need to paint on worm-eaten wood. Other evidence is nails, long and machine-made, which are hidden from view, but which x-rays clearly reveal ”.

It is evident that the use of a ready-made ancient support would have nipped in the bud the problem of artificially conferring to this portion of the fake the characteristics of the ancient original in terms of nails, choice of wood treatment, aging, etc.

Fake signatures

Signature added after the craquelure had formed

For this reason, a forgery technique widely used in the past, even if currently falling into disrepute, precisely because it was too exploited, was to ennoble genuine paintings with false signatures by illustrious artists. Still in use, as we have said, is the practice of suppressing the signature of secondary artists, opening the way to a more ambitious attribution.

In this way the genuine parts of the work share with the integrally original objects the ability to resist not only the analysis foreseen by the forger, but also other possible future verifications, of which it is impossible to prevent the results when falsifying from scratch, producing pieces fully modern.

To what extent authentic?

Althofer [14] writes that commonly on the market appear not pure fakes but mixed objects that lead one to ask oneself not if they are “authentic or false?” but rather “to what extent authentic, to what extent false? Pure counterfeits, to which this concept is applicable without restrictions, both from the point of view of technical investigation and from the legal point of view, are relatively rare ”.

From these and from the previous considerations it can be deduced that there cannot exist methods of investigating and revealing the fake, but only empirical criteria, even if they are taken from the aid of some technical sciences.

First among all, however, since the forger imitates works of art, is the aesthetic criterion: fraud leads the forger to create his work inspired by various archetypes and it is rare that a confusion of styles, disharmony and concealment does not result, these signs of the style of the time can easily betray artifice.

Scientific investigation

Alongside the aesthetic and critical investigation there is a group of chemical and physical experiments aimed at determining the properties of matter (its structure, its age) in the object whose authenticity is questioned.

The micromethods are crucial, that is the study under the microscope of small samples taken from the work which, chemically and optically detecting the composition of the material, allow the identification of the binder, the pigment, the varnishes present in the painting. The section of the fragment reveals the successive stratifications of the material from the paints to the support. The shape and size of the pigment make it possible to distinguish a manual color grinding from an industrial grinding.

Often a simple magnifying glass is sufficient to reveal a deceptive craquelure, achieved by strongly heating the surface and subsequently tempering it with cold water or through the addition of chemical substances that accelerate the drying: devices used to accelerate, in the matter, that seasoning and consumption that only the natural event of time can provide.

The raking light, or tangent light examination, facilitates the critical reading of the painting by highlighting the reliefs of color and brushstrokes.

The infrared and ultraviolet radiations allow an evaluation of the extent of the overpaintings even if cleverly disguised; while with employing X-rays it will be possible to take note of the real extent of the gaps, of the wear of the pictorial layer, as well as of the progression of the brushstrokes that, from the depth of the priming, make up the picture right up to the surface.

Dating techniques

There are also extremely complex and sophisticated techniques that make it possible to establish the age of the materials used such as potassium-40, uranium-238, rubidium-87.
In particular, the characteristics of metallic lead are used to determine the age of oil paintings. The radioactivity of this element, in fact, is much higher the older it is: it is therefore sufficient to measure the activity of lead colors, in particular of white lead, to establish, for example, whether a painting was made in this century or in last one.

In case the organic materials are available in insufficient quantities, research will be made based on C14, that is, the residual radioactivity of the carbon of organic origin contained in these substances. Since, over time, the area of ​​activity fades, the measurement of its intensity will lead to a sufficiently approximate chronological determination. Industrial activities, nuclear experiments and, in general, atmospheric pollution have increased the C14 content in organic substances to the point that it is possible to accurately determine the paintings painted after the end of the Second World War.

Currently, instruments are used that can analyze very small quantities of the find, of the order of milligrams thanks to the accelerator mass spectrometry technique (AMS).

To all these instruments of investigation, the counterfeiters will oppose an increasingly astute technique, using ancient materials, using tricks that are less and less evident to the physical and chemical eye, so that the history of falsification and the discovery of fakes can be said to accompany that of discoveries. again the means of physical and chemical investigation.

Note

[1] Cesare Brandi, Il concetto di falsificazione, contributo alla voce falsificazione in Enciclopedia Universale dell’Arte, Venezia, Roma 1961, vol. V coll. 312-315

[2] Carlo Ludovico Ragghianti ,Coscienza e conoscenza dell’individualità, Pisa 1961

[3] Otto Kurz, Falsi e falsari, neri Pozza 1961

[4] Frank Arnau, Arte della falsificazione, falsificazione dell’arte, Feltrinelli 1960

[5] Max  J. Friedlander, Il conoscitore d’arte, Einaudi 1955

[6] L. Vlad Borrelli, Storia ed aspetti della falsificazione, contributo alla voce Falsificazione in Enciclopedia Universale dell’Arte, Venezia, Roma 1961 , vol. V coll. 315-319

[7] Vasari, Le Vite de’ più eccellenti architetti, pittori, et scultori Italiani, Da Cimabue insino a’tempi nostri: descritte in lingua Toscana, da Giorgio Vasari Pittore Aretino. Con una sua utile e necessaria introduzione a le arti loro, Firenze, Lorenzo Torrentino 1568; ed. cons. a cura di G. Milanesi, Le opere di Giorgio Vasari , Firenze, Sansoni 1981 vol.VII pag 117

[8] Vasari, V, pag 369

[9] Vlad Borrelli, cit.

[10] E. H. Gombrich, La storia dell’arte raccontata da E. H. Gombrich, Einaudi 1966 pagina 22.

[11] Giovanni Urbani, Falsi di arte medievale e moderna, contributo alla voce Falsificazione in Enciclopedia Universale dell’Arte, Venezia, Roma 1961 , vol. V coll. 319-321

[12] Vlad Borrelli, cit.

[13] Kurtz 1948

[14] Heinz Althöfer, Il restauro delle opere d’arte moderne e contemporanee, Nardini 1991