Skinning of the pictorial surface due to the use of aggressive substances

A large part of the damage on paintings seen today is a result of past cleaning interventions. Between the Sixteenth and Eighteenth Centuries, no distinction was made in terms of the type of dirt to be removed. Each cleaning “recipe” could be used indifferently on frescoes as well as on panel paintings. From the earliest written recipes dating from the Sixteenth Century, the use of hot lye was recommended. The lye was made from the “strong ashes” of the oak tree in combination with quick lime. Other substances were added such as soap, egg, salt or honey and then this mixture was applied to paintings with a sponge. It was removed with another sponge soaked in water as soon as the work appeared to be clean. In reality, these substances did not have an action limited solely to the dirt and varnishes, but also attacked the binder, resulting in the internal break-up of the medium and the continued action over time of the mixture – even after the apparent washing and removal. The pictorial layer, which was at that point without much of its cohesive material became powdery and flaked off.

Abrasioni della craquelure dovute ad interventi con sostanze corrosive

Abrasions of craquelure due to interventions with corrosive substances

In addition to the use of reagent solvents such as sodium hydroxide and potassium hydroxide, or other types of alkaline or acidic corrosive substances, the techniques and materials adopted for quick results were quite varied. We know that one of these consisted in wetting the pictorial surface with wine spirit, that were then set aflame. The goal of this treatment was to soften those layers that had to be removed. Also employed were “pomades” made up of fanciful components. (It was not uncommon to use urine in these compounds). Also, abrasive substances were often used. The mechanical action of the sponges and the brushes rubbed on the surface during the application and removal of these various concoctions played a major role in the final damage. The surfaces of paintings treated in these ways are today more or less heavily abraded. This is particularly true for those points were the craquelure lines cross one another. This gives the surface an appearance of being full of holes and highly skinned.

Ridipinture di parti sporche o abrase

Overpainting of dirty or abraded parts

All of these cleaning methods were often a result of other – equally damaging – practices carried out on paintings. Before any important religious festivals, it was normal practice for example to rub the surface of a painting with a rind of bacon, or even to clean it with an onion. Often the works were then wet down with boiled linseed oil. Notwithstanding the immediately captivating results, over time this treatment formed thick, dark crusts. In addition, having completed the cleaning operations, the painting usually underwent some type of retouching or overpainting to revive the colors and bring the image “up-to-date” with respect to the fashion or the iconography of the moment. Often, the “restoration” intervention consisted in the simple overpainting of all the dirt-filled areas. Respect for the work of art in the context of historical and cultural testimony was still long off in the distance. As Giovanni Secco Suardo accused in the 1800’s: “the number of paintings barbarously exterminated are not only skinned but also stripped entirely” – and then calmly repainted.

Modifica parziale della composizione

Partial modification of the composition for religious or taste purposes

In addition to the damage created by an insistent cleaning, other causes that bring the painting to the point of being overpainted can be identified.
Often, one must treat naturally aged areas or areas that have undergone accidental alterations (rips, tears, cuts etc.). In other cases however, the total or partial modification had aesthetic, historic, political, religious or commercial ends; that is, meant to follow changes in fashion or market changes

Ridipintura effettuata al fine di aggiornare l'opera

Repainting carried out in order to update the work

Therefore, we can find works today that have been fairly well “manhandled”; works that rather than documenting the figurative culture of the period in which they were made, testify to the taste of those who re-read the work during that particular period when it was “restored”.

Manfredi Faldi – Claudio Paolini

artisEstratto 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, coordinati dall’Istituto per l’Arte e il Restauro Palazzo Spinelli, con il determinante contributo della Commissione Europea nell’ambito del programma d’azione INFO2000.

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