A simple trick, according to the internet, is that you can clean practically anything with bread. This, like all hyped miracle cures, should be taken with a very large grain of salt…and maybe some milk, mustard, saliva, egg yolks, ash, vitriol and a host of other ingredients suggested over the centuries for cleaning paintings .
After all, art restoration is not an invention of the twentieth century. Scholar Ulrike Kern explores The Seventeenth-Century Documentation of Theodore de Mayerne of the art and craft of taking care of paintings and works on paper. In 1632, De Mayerne himself, as his own invention (a debatable point), advised the soft insides of “stale brown bread” to gently remove dirt on distemper paintings. Kern writes that the “method of removing dirt with fresh bread or a kneadable eraser is still used because it does not require rubbing to make the top layers of dirt stick to the medium.”
Theodore de Mayerne (1573-1654/55) was a Huguenot physician employed by both King James I and his son Charles I. He also had a great interest in the materials and techniques of painting. To be Pictoria sculptoria tinctoria et quae subalternarum artium spedantia in lingua Latina, Gallica, Italica, Germanica conscripta a Petro Paulo Rubens, Van Dyke, Somers, Greenberry, Janson &., Fol. no. xix, better known as the De Mayerne Manuscript, was compiled into 170 folios from the 1620s to the 1640s. Today it is held by the British Library.
De Mayerne consulted half a hundred artists for the composition, including Peter Paul Rubens (who painted his portrait) and Anthony van Dyke. All this makes him, Kern writes, “one of the founding fathers in the history of… [art] conservation.” The manuscript was rediscovered in 1847 – another important De Mayerne manuscript was found in 1967 – and for over a century has been studied primarily for its “utility in reconstructing seventeenth-century painting processes.” manuscript under restoration, some of the “earliest and most comprehensive documents” on the subject, have recently received more scholarly attention.
The first reported attempts to restore painting date back to antiquity, but there were few written records on the subject before the seventeenth century. Before De Mayerne, there was no such thing as a professional photo restorer; artists, amateurs or collectors have tried to clean and restore them themselves, with varying results. Since De Mayerne essentially took notes of everything he heard and tried, his suggestions are “far from unproblematic.” Some, such as the use of strong acids and carpenter’s glue, would certainly no longer be used today, when the techniques of painting restoration can still lead to heated discussions. “We’re not sure whether all the methods that De Mayerne recommended were actually applied,” Kern notes.
So why did this court doctor have a side job in art restoration? It is not certain, but the arrival of paintings “as black as ink” from Lombardy “seem to have had special significance” for him.
In 1627-1628, Charles I bought a large art collection from the Gonzaga family of Mantua. One particular ship arrived in London with paintings that had blackened during the voyage. De Mayerne thought this was due to a combination of fermenting currants and sublimated quicksilver (mercury) stored in the hold next to the paintings. The doctor’s speculations about the blackened paintings were “probably not entirely accurate,” Kern writes, but his explanation of the cleaning process still stands.
The ship’s oil paintings were washed with milk, after experiments with “saliva, then saliva mixed with warm milk and, for the most stubborn blackening, warm aqua vita (spirit of wine).” Kern notes that “mild enzymatic detergents and sometimes even saliva are still used today.”
Nevertheless, Kern concludes that most of De Mayerne’s techniques not are applied today. But “the fact that they were written down and developed in part through further experimentation marked a significant advance in the disciple of photo restoration.” De Mayerne’s manuscript is a remarkable account of trial and error, hearsay and practice – the true blueprint of a discipline at birth.