The information obtained from examinations using raking light, transmitted light, ultraviolet fluorescence and the infrared spectra can be further detailed by enlarging the image. Macrophotography should not however be considered an important investigative technique only when it is combined with other types of examination. With macrophotography there is the possibility of isolating small areas of the work and concentrating one’s attention on details that are invisible to the human eye. (The eye cannot perceive the separation between two points or lines that are less than 1/5 of a millimeter apart). At the same time, the comparisons and the documentation data along with other images can be of great interest in the field of restoration and art history.
Macrophotography allows the painter’s style to be studied by pointing up its characteristics. It is indispensable for a comparison between various works, where the brushstrokes, their direction, length and curvature, and examination of the relief of the paint can be compared. It is important to maintain the small scale throughout the reproductions, the original brushstroke being used for comparison purposes with the ones under examination. To this end it should be remembered that the reproduction relationship is expressed by a proportion that indicates the relationship between the actual dimensions and the image reproduced on film. For example, 2:1 means that the dimensions of the image are in relation to the real dimensions as 2 goes into 1. Naturally, the raking light examination and macrophotography can be combined, for example, to give even more relief to a brushstroke. This is especially true when the color is applied in a thick impasto. This type of examination can show aspects of the painter’s style and the quality of the pictorial surface that can be of great assistance in making an attribution.
The principals on which an attribution is based are very simple. On one hand, there is the ability of the human mind to recognize something it already knows. On the other, it is a characteristic of man to always leave some kind of personal imprint – whether is conscious or not – on what he does,. The Abbott Luigi Lanzi wrote at the end of the 1700’s, “nature gives each one of us a way of writing that is difficult to imitate and to confuse entirely with another. A hand that is trained to move in a certain way always retains that movement: in old age, writing becomes slower, more difficult, heavier but the character itself does not change. It is the same in painting. It is not just a loaded or lean brush that identifies a painter…that can be similar among many, but in the movement of the hand, the turn of the brush, lines that are more or less curved, more or less candid or studied, that is entirely his own.”
A highly magnified enlargement allows various characteristic elements of the cracking to be seen. This phenomenon is rarely missing from antique paintings and by observing it, we can establish its causes: traction from the support (ageing cracks), the use of improper or incompatible materials (drying cracks).
In other cases the examination can help to identify cracking caused artificially – even though this is not a definitive element in the recognition of a fake.
Not infrequently, certain aspects of a work can be documented with macrophotography that are surely falsifications, as in the case of the ageing cracks interrupted exactly where a signature is placed.
The observation of the pictorial surface under high magnification can point up sudden interruptions of the original craquelures or clarify the presence of craquelures with a dubious nature such as those made by the restorer by painting or scratching the area that was restored. Differences in the make-up of the surface of the original pictorial layer with respect to the overpainting can often render the identification of the boundaries of an original area from a later pictorial intervention more precise. Macrophotography helps to form a fairly good idea about the extent to which a specific painting is re-worked.
Naturally, the raking light examination and macrophotography can also be combined to better determine the level of adhesion between the painted layers. The smallest areas of flaking and separation of paint from the ground preparation, and/or ground preparation from the support, as well as all the other surface defects, can be analyzed and documented. This can assist the restorer in any localized interventions that must be undertaken and will allow for the verification of the result once the intervention is complete.
The very highly magnified enlargement that can be obtained with macrophotographic techniques can evidence the true condition of the pictorial film: abrasions, small lacunae, residues of old varnish – or as in the case of this image – corrosion at the edges of the craquelure as the result of a previous cleaning intervention using very aggressive solvents, can all be documented.
Manfredi Faldi – Claudio Paolini
Estratto da: Artis (Art and Restoration Techniques Interactive Studio), Direzione scientifica: Manfredi Faldi, Claudio Paolini. Cd Rom realizzato da un gruppo di istituti di restauro europei, con il determinante contributo della Commissione Europea nell’ambito del programma d’azione INFO2000.
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