The ambitious exhibition programme at the National Galleries of Scotland regularly provides the impetus for the Conservation Department to investigate a work of art which, for reasons of poor condition, may not have been on public display for many years.
One such candidate came to light during preparatory research for a major exhibition, focussing on the life and court of King James VI and I, which will take place at the Scottish National Portrait Gallery.
The artwork in question is a small portrait of James’s eldest son and heir, Henry Frederick, Prince of Wales (1594-1612), painted by an unknown artist.
It was acquired by the National Galleries of Scotland as early as 1915, with minimal information regarding its provenance.
The exhibition curator, Kate Anderson, was keen to include the painting in the exhibition, but at first glance this looked unlikely; Henry's image was barely legible and his features were disfigured by deeply discoloured layers of both varnish and restorers' overpaint.
So, how did the painting conservator proceed?
The initial focus of any conservation project is based on intensive looking - a thorough examination of the portrait using several different techniques. This allows an informed decision as to the feasibility (or not) of treatment being undertaken.
In this instance, the conservator was aiming to ascertain how well preserved the original Henry was beneath the applied layers in order to decide if it was worth allocating precious resource to make the painting fit for display.
Firstly, the painting was X-rayed. A long- established technique for the examination of paintings, this can offer invaluable information both on how the painting was made and its condition.
The support of the painting consists of an oak wood panel, whose original thickness has been significantly reduced in the past.
The X-ray image was not easy to interpret due to the presence of a 'cradle' on the back of the panel; this is an elaborate lattice structure, which was attached at some point in the panel's history with the aim of keeping it flat and preventing splits in the wood from opening up.
However, further information was provided by a second type of investigation, infrared reflectography which uses waves of light from the other end of the electromagnetic spectrum.
The results of the infrared reflectography were dramatic and unexpected: it revealed a second pair of eyes looking out from Henry’s portrait, giving clear evidence that ‘our’ Henry was painted over an earlier portrait!
Also – curiously - the underlying eyes appear to have been deliberately scratched out. The astonishing discovery of a second portrait whetted our research appetite and the decision was made to continue our investigation by cleaning the painting, which entails the removal of non-original, darkened layers of varnish and overpaint.
When it is first applied, varnish provides protection for the paint layers and saturation of the colours, making them appear richer and more vibrant.
In the past varnish was invariably composed of a natural resin (dammar or mastic) and over time this layer, exposed to air and light, naturally degrades. The varnish changes colour and becomes semi-opaque, creating an unwelcome barrier between the viewer and the artist’s intended image.
Additionally, the infrared reflectography had shown that there were considerable areas of overpaint on the painting.
These had been applied during previous, undocumented restorations, primarily to cover areas of damage. Like the varnish, this overpaint tends to obscure the original image and it also changes colour with time.
With mounting levels of trepidation and excitement, the cleaning began with tests using a range of solvents.
The most effective solutions were then applied with cotton wool swabs, to thin the layers of overpaint and varnish in a gradual and controlled manner.
In addition, a strip of chalky filling material, inserted at some point to hide a small step in a repaired vertical split, was revealed beneath the overpaint.
This material was easily removed using a small scalpel under the microscope and a large area of perfectly preserved original paint was uncovered – a deeply satisfying result!
Thankfully, today’s audiences are generally understanding of the tangible consequences of the ageing process and can accept that a wooden panel dating from 1612 is unlikely to be perfectly flat.
This is how our portrait now looks at this ‘during treatment’ stage.
Aside from the dramatic change in colour, the degree of paint loss or abrasion may appear somewhat alarming, but it should be remembered that the portrait of Henry is now over four centuries old, and so some level of damage is to be expected.
It is often the case that a painting part-way through its conservation treatment looks worse than it did to start with!
So what happens next? Do we have enough information to identify the artist who painted Henry? Who is represented in the portrait beneath and why was this image then concealed? And what will the conservator do to make this damaged painting fit for display?
To be continued...