Everyone looking at The Night Watch now will notice its new aluminum strainer to which the lining canvas is now attached. For the spring technique that was used to retension The Night Watch a total of 86 springs attached to stainless rods inserted in a casing around the perimeter of the painting make sure the tension in the canvas is always evenly distributed. The Italian paintings conservator Antonio Iaccarino Idelson, who is specialized in stretchers and tension systems, has been developing this technique since the 1990s.
Student
In 1989, Antonio Iaccarino Idelson was a student at the Istituto Centrale per il Restauro (ICR) in Rome when a Caravaggio painting was brought in for treatment. In 1984, Caravaggio’s St. Jerome Writing (c. 1607–1608) was stolen from the St. John's Co-Cathedral in Valletta, Malta. Thieves had cut the picture out of its frame and two years later when it was recovered it was in need of restoration before it could go on display again.
Roberto Carità
Iaccarino Idelson: “The strainer used for The Night Watch is an innovation developed by Roberto Carità, an Italian art historian and conservator, who also had an engineering background. Working at the ICR from 1953 until 1960, Carità developed innovative techniques for the structural conservation of paintings, including the elastic spring system that he used on the Caravaggio painting. Carità used springs that he bought from the Vespa shop across the street to attach the painting to its strainer. After he left the ICR in 1960 his spring system was discontinued, and his innovative approach was largely forgotten. Still, after more than 60 years, none of the masterpieces that were retensioned with Carità’s method suffered from tension-related stresses.”
Elastic spring system
Studying this application, Iaccarino Idelson further developed ICR’s work on the elastic spring system. The goal was to further the understanding of the relationship between the painting and the stretcher as a function of tension. The company Equilibrarte, which Iaccarino Idelson co-founded, has successfully used the technique on several hundreds of paintings including masterpieces by Titian, Rubens and Miró. The technique has been used on paintings varying from very small to very large, up to 10 x 5 meters.
The Battle of Waterloo
In 2012 Equilibrarte successfully retensioned the biggest painting in the collection of the Rijksmuseum, Jan Willem Pieneman’s The Battle of Waterloo (1824), which measures 567 × 823 cm, and like The Night Watch, is also wax-resin lined. At the moment, apart from his involvement with The Night Watch, he is working on a large ceiling painting François Ier prêtant le serment des chevaliers (c. 1819) by Alexandre Evariste Fragonard in Musée du Louvre, and a large-format, irregularly shaped canvas by the American artist, Frank Stella, Isfahan III (1968), at Museo de Solidaridad Salvador Allende in Santiago, Chile.