'Een doek van geene beteekenis' De nachtelijke samenzwering van Claudius Civilis in het Schakerbos van Govert Flinck en Jürgen Ovens technisch onderzocht
Authors: Hommes Margriet van Eikema , Froment Emilie 
Published: November 2011

AbstractBecause of its extreme darkness, The nocturnal conspiracy of Claudius Civilis by Govert Flinck (16151660) and Jürgen Ovens (1623-1678) holds an isolated position within the decoration program with the Batavian revolt in the galleries of Amsterdam's former Town Hall. Of course the canvas depicts a nocturnal scene with light from only the fire and the moon, but in this painting the darkness dominates virtually everything. The rough, rather sketchy execution, whereby large parts of the canvas are left unpainted is also peculiar. Because of this appearance, some art historians have thought it an outrage that this 'painting with no value' should have replaced Rembrandt's masterpiece with the same subject.
However, Flinck and Ovens – both pupils of Rembrandt – were painters of the first rank and there is nothing in the oeuvre of either master that is reminiscent of this rather unbalanced gallery painting. The question is therefore: to what does this piece owe its inaccessible appearance? This, of course, also relates to the manufacture-process and function of the canvas. Archival records and historical texts contain many relevant details on the paintings' genesis but have so far mainly given rise to confusion.
The technical investigation, carried out during the 2007-2009 conservation campaign of the Batavian series, now demonstrates that the painting's extreme appearance traces back to both its peculiar genesis that is wholly different from that of the other gallery paintings and to its unfortunate conservation history.
It was found that the piece was never intended to be a permanent decoration: the canvas is the one surviving remnant of a series of temporary festive decorations that Flinck had produced in the summer of 1659 in honour of the visit of Amalia van Solms and the Orange family to the Town Hall. Because of the painting's temporary nature, Flinck has modified his usual working procedures. Rather than taking sturdy, durable linen he chose a thin, fine canvas; and instead of applying to his canvas a reliable ground layer he painted on it directly. Flinck elected for fast-drying water-based paint (gum arabic) and worked with an extremely modest palette: he coloured his canvas with a thinned brown paint and on this base modelled his figures with only black contours and beige highlights.
The original idea was that Flinck's temporary works would be replaced by permanent decorations from his hand, consisting of twelve paintings. But because of his untimely death in 1660, the commission was divided between Jordaens, Lievens and Rembrandt. Rembrandt's painting, to replace Flinck's work with the nocturnal conspiracy, was almost immediately removed, probably in the summer of 1662. When the Bishop of Cologne visited Amsterdam shortly afterwards, this empty space needed to be filled in a hurry and Flinck's old decoration was retrieved from storage.
Jürgen Ovens was commissioned to 'work up [= finish] a sketch by Govert Flinck into a complete ordonnance'. Once again we seem to be dealing with a temporary decoration, for the modest sum of 48 guilders was all that Ovens was paid. The painter only did what was absolutely essential – after applying an isolating glue layer, he just added a few lines and touches of colour in oil paint here and there, all just enough to clarify Flinck's image, which was by then probably somewhat battered.
The planned replacement of the Flinck/Ovens' canvas by a permanent painting never materialized; oppressed by a shortage of finance, the city governors decided in 1664 to postpone for five years all commissions or purchases of paintings for the Town Hall. This is why Flinck's canvas, dressed up a little by Ovens, has remained in the gallery to this day. Obviously, this painting, produced for a strictly temporary purpose, was never intended to have such a long 'life'.
An ungrounded canvas painted with water-based paint is highly fragile and discolours as the fabric ages. But quite apart from this discolouration the dark and empty impression that the painting conveys today, is mainly due to earlier treatments by those who had no understanding of its unique characteristics. As archival records show, in the eighteenth century the canvas was lined twice using glue; a treatment that involved the use of considerable amounts of water. In addition, over the centuries the painting has been varnished several times and in the 1960's it was given a wax-resin lining. It is because these treatments, each of which is totally unsuitable for a water-based canvas, that the painting has acquired its present patchy and dark orange-brown appearance.
Since nothing can be done to remedy the consequences of the lack of understanding of previous centuries - one cannot return to the painting's original appearance - the aim of the recent restoration was to achieve a balance between the aspects of the painting that stem from its unusual manufacture-process and the qualities that are the consequence of its conservation history.