Musidora – oil on cardboard – Manfredi Faldi 2016 (detail)
In the artistic field, the phenomenon of fakes and falsification requires reflection on the material aspect of individual works of art. Modern art history studies are developed following different methodologies, but all seem to somehow move from a vision of the work of art as separate from the matter of which it is made. This same matter, however, rebels and steps back in the foreground when the authenticity of the work itself is questioned. The authenticity of a work of art is in fact the essential condition for any further consideration to have a real “value”.
The forgery of works of art

Copy from an existing original
Fakes in art – Introduction
Tackling the theme of forgery in the art sector can therefore be an opportunity to study the work, primarily from a material point of view, in search of that same artistic value, albeit through a different path.

Duccio di Boninsegna – tempera on wood panel
Definition
The definition of artistic forgery, of which Cesare Brandi provides an unsurpassed analysis, immediately removes the temptation to see in the forgery only a case of commercial fraud, making us, instead, consider the forgery together with the copy and imitation, as documents of the cultural level, of the critical orientations, of the taste and prejudices of an era (see C. Brandi, EUA).
History is full of examples of falsifications in the field of art which, up to the formation of a conscious critical judgment, are not even distinct from the original production. From the documented examples it is clear how much the historical, cultural and economic influences of each era gradually influence the critical interpretation and, consequently, the realization of the reproduced object. Almost making it possible to derive a history of changes in taste and critical-cultural orientations.

Aged copy
Investigation
Art historians, restorers and scientists have for years been allies in trying to unmask all forms of falsification in art. Each supposedly false work will thus be aesthetically investigated by historians and critics in search of errors and stylistic anachronisms, the restorer will investigate all the technical requirements that the work should have, from the support to the pictorial layer while all the possible scientific methods above and below the visible surface will be used to discover new irrefutable evidence and elements that can contribute to the judgment of the first two categories of scholars.
But to all these instruments of investigation the forgers 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 and prompt that of the discoveries of new means of physical, chemical and historical-artistic investigation.

Painting done after an ancient print
Categories
Referring to artistic production, the forgery is commonly understood as an object made with the specific intention of deceiving about the author and the time of its execution; mostly this understanding is confirmed by the placement of the work on the market.
Fake paintings can belong to different categories: copies taken from existing originals (sometimes made with the intent of study) and later passed as originals; forgeries without model (sometimes made in the style of a specific author of which drawings and studies are not made pictorial) pasticci, that is, objects composed by bringing together single elements taken from authentic material and often belonging to the same author; finally alterations, tampering and adaptations of existing works, with the intention of increasing their value.

X-ray radiography
Alterations
This last category is by far the largest, so much so that it is often incorrect to ask “authentic or fake?” but rather, as Althofer, a modern-day specialist writes, “to what extent authentic, to what extent a fake? Pure fakes… are relatively rare ”. From this it can be deduced that scientific methods can rarely prove falsehood and never guarantee the authenticity of a painting; the primary tool therefore remains the aesthetic judgment even if drawn with the aid of some technical sciences.
Some investigations such as X-ray radiography are, for example, able to reveal the original material hidden under the repainting, but it will certainly not be a quantitative evaluation to determine whether the work has been reconstructed in a decisive way and the artistic value can be considered canceled.

Blue pigments
Chemical analysis
Many fake works have been unmasked through the chemical analysis of color, that is, by identifying pigments still unknown at the time the painting should have been produced. Neither titanium white nor zinc white may, for example, have been used by an Eighteenth-Centurypainter, as the two pigments were available from 1920 -the former- and from the end of the Nineteenth Century -the latter-. Of course, there should be no doubts about the representativeness of the analyzed samples, which must come from areas without touch-ups and not contaminated by other materials.
Recently the art literature has been enriched with in-depth studies on the palettes used by the great artists of the past, but of course the forgers were among the first to take an interest in new research. The investigation to establish the authenticity of the paintings therefore leads on the one hand to the discovery of ever new technical stylistic features and on the other, stimulates the creation of increasingly refined fakes.

Perimetric nailing to the original support
The supports
Even the preparation often contains white or other colored pigments that can help unmask a fake, moreover the gypsum used as an inert in the preparations of northern Europe before 1850 was only available in its natural form: the examination with an electron microscope will therefore allow to distinguish it from the newer man-made product.
Canvas supports are more difficult to evaluate chronologically than is commonly thought. In fact, even if it is theoretically possible to date a canvas from its specific texture, in practice there are no sure references and the only certainty remains for pre-treated canvases, in use only since the end of the eighteenth century. Much attention must be paid to the perimeter nailing and to the original frame in the rare cases where they are maintained. The marks left by these along the edges of the canvas should not, however, be underestimated as they are difficult to reproduce.

Wooden support
Dendrochronology
For the oak wood supports used by the old Flemish masters, there is an interesting examination that allows us to accurately date the year the tree was cut down which generally corresponds, albeit with a small difference, to the year of the painting. The exam is based on the comparative study of the shape of the plant’s annual growth rings and is called dendrochronology. It is always necessary to be very cautious before making judgments on the authenticity of a work, not limited to the results of a single examination: in this case it is necessary, for example, to evaluate the possibility that the painting has undergone a replacement of the original support to a transport operation and we are therefore faced with an ancient work with a recent support, just as it can happen that the forger has reused an old support and is in the opposite condition.

Surface with woodworm holes and tunnels
Reuse of old supports
Holes and tunnels of woodworm on the surface, filled during the spreading of the preparation, can be revealed by X-ray radiography. The extreme attention that the ancient masters used to prepare their works allows to exclude the possibility that they used worm-eaten wooden supports. Often, however, the forgers have not limited themselves to using old tables but have painted their works on top of ancient paintings of little value. The removal of the original painting is not always complete, both due to the difficulty of the operation and the risks of ruining the precious support, so that some examinations such as radiography can reveal the presence of underlying compositions from a later period than the one that was initially presumed. It should also be noted that in radiography the fakes, like all copies, often turn out to be rather transparent and uniform, there being only the concern to imitate the visible surface of the painting, working with caution, without spontaneity and with a brush lightly loaded with color.

Anomalies of the craquelure
Craquelure
The study of the pictorial characteristics in the depth of the structure of the painting has also made use, for some years, of the infrared reflectography technique which, often making it possible to observe the preparatory drawing, contributes greatly to clarifying doubts about the nature of the object.
It can happen frequently to document aspects of sure fraudulent character using macro-photography , as in the case of aging craquelure interrupted in correspondence with the painting with which the signature was made, or other anomalies of the craquelure, typical element of every ancient painting that the forger must never neglect. Just as he will never have to forget, if he wants to pass his work as ancient, “the alcohol test” and “the nail or pin test”, trying to ensure sufficient resistance to solvents and pressure on the painted surface.

Ultraviolet fluorescence examination
UV fluorescence
On the other hand, the ultraviolet fluorescence examination is of little relevance in order to judge the antiquity of a painting. It is true that the painting observed under Wood’s lamp acquires, over the years, brightness, and that the colors lose their bluish components taking on a yellowish tone, but the phenomenon – in addition to being difficult to quantify – is influenced by the material used originally, the overlapping layers over time and the storage conditions.

Honor Daumier
Achilles and the tortoise
Finally, there are extremely complex and sophisticated techniques that make it possible to establish the age of materials such as mass spectrometry. To determine the age of an oil painting, the level of radioactivity of the lead contained in some pigments used in painting is studied. The decay reactions generate different isotopes whose ratio can vary according to time and geographical origin. The complexity of the analysis and the high cost of the equipment, however, greatly limit the use of mass spectrometry in the field of art.
To all these instruments of investigation the forgers will oppose an increasingly astute technique, using ancient materials, using tricks 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. of new means of physical and chemical investigation.
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