Removal of varnish and old retouchings

Cleaning tests had revealed that the old varnish - applied by Horace Buttery in 1960 - could be removed using standard cleaning solutions without risking Poussin's paint surface. So what do we mean by a standard cleaning solution?

Crossing the Red Sea - literally!

It is a delightful quirk of fate that Poussin's  Crossing of the Red Sea   has actually crossed the Red Sea - three times in fact.

Previous restorations

Has the   Crossing of the Red Sea   been restored before? Certainly. You could say that most Old Master paintings have been cleaned at least once during each century of their existence, so it is quite possible that our painting has been cleaned at least four times.

Do we know when and how it was cleaned? Not entirely. The thorough documentation of conservation treatments is a rather recent phenomenon. Only a handful of art museums around the world have concise records of treatments carried out before World War II, and many do not have much in the way of reporting before the 1960s. For works in private collections, conservation records have been almost non-existent.

The revelations of UV photography

As we draw closer to the cleaning of the  Crossing of the Red Sea   we turn our attention to UV photography. A quick glance at an image of the painting under ultraviolet light is enough for a conservator to learn some of the critical issues regarding its surface, especially the condition of the old varnish and the previous restorer's work.

A strategy for cleaning, Part 2

With testing out of the way it is now time to commence the varnish removal. It comes as a surprise to some people to learn that the cleaning can be a relatively quick part of the restoration process. With the   Crossing of the Red Sea   we have anticipated that the cleaning time required will take up only one month of the twelve we have set aside for the treatment, though that will be subject to revision if we encounter any unexpected problems.

A strategy for cleaning Part 1 - testing

With the documentation and examination of the painting now well underway, the time has approached to develop a strategy for cleaning the painting, that is, the removal of the discoloured varnish and restorer's overpaints. While every cleaning must follow the particular demands of each individual painting, the steps we will take for the   Crossing of the Red Sea   are typical for the treatment of many old master paintings.

X-raying the Poussin

Paintings have been examined by radiography ever since x-rays were first discovered by the German physicist Wilhelm Röntgen in 1895. Today, over a hundred and fifteen years later, there is still no more useful tool for the conservator than radiography because it can provide information about so many components of the painting. Other valuable examination tools, such as infrared imaging or microscopy tend to be more specific in their application.