 
The famous painting "Girl Reading a Letter at an Open Window" by Johannes Vermeer
is one of the greatest treasures of the Gemäldegalerie Alte Meister in Dresden.
Today, only about thirty-five paintings are attributed to the great 17th-century Dutch painter.
One of the artist’s early works, the painting
came to Dresden in 1742 from the French collection of the Prince of Carignano.
It was ascribed to Rembrandt at the time.
Although the actual artist’s name appeared in a guide to the Dresden gallery as early as 1806,
the attribution to Johannes Vermeer – to the Sphinx from Delft,
as this mysterious painter was also called – only became established in Dresden
Gustav Thoré-Bürger in 1859.
Worldwide, Vermeer’s paintings are among the most thoroughly researched and documented works of European painting.
In the past decades, most of his paintings have undergone thorough restoration.
A comprehensive restoration of the painting had been on the agenda of the
Gemäldegalerie Alte Meister at the Staatliche Kunstsammlungen Dresden for quite some time.
“The restoration work on the painting Girl Reading a Letter at an Open Window by Johannes Vermeer
was preceded by a long and intensive preparatory phase,
which resulted in this decision.
This phase began around 2004-2005,
when the Gemäldegalerie’s second painting by this artist was being restored by Marlies Giebe,
revealing tremendous colour.
It was at that time that the desire emerged for Girl Reading a Letter
to be shown in its original appearance as well.
It should also be mentioned that, in the spring this year,
we met with specialists from Vienna, Amsterdam and Copenhagen
and discussed the concept for this restoration, gaining of course a wealth of suggestions from them:
what to look out for during the restoration,
which further tests should be carried out
and how the testing programme as a whole should be structured.”
Dr. Christoph Schölzel, conservator at the Gemäldegalerie Alte Meister for many years,
presented a proposal for the restoration.
After further discussions, during which the pros and cons of such a restoration were weighed,
the experts involved spoke in favour of the undertaking.
Christoph Schölzel was entrusted with the restoration of the painting.
The science lab at the Hochschule für Bildende Künste Dresden became a partner in this cooperation.
Support also came from an expert commission.
The first step was to remove the varnish,
the protective layer that covers the original paint
but has yellowed and browned with time,
thus dimming the radiance of the layers of paint underneath like sunglasses.
To remove layers of varnish,
the conservator uses cotton swabs
soaked in organic solvents.
Carefully, he advances in small steps,
constantly checking the cleaned areas,
including under the microscope.
With Vermeer’s Girl Reading a Letter,
removing the yellowed varnish
amounted to a rediscovery of the painting:
The painter’s finely modulated colours re-emerged
and the painting once again radiated in its cool, finely nuanced colours.
As the varnish removal progressed to the left edge
of the overpainted background surface in the centre of the painting,
the restorer noticed that the paints used in the overpainting layer
responded differently to the solvents compared to the layers that had not been overpainted.
“Commonly, when varnish is removed,
inks applied later are dissolved as well,
like those perhaps used during the 19th-century restorations of the Dresden painting.
But in this case, we were aware
that there are a number of overpainted areas
along the edge and especially in the background above the girl’s head.
When I noticed that the solubility parameters of the paint layers
in this area differed from those of the original paint layers,
we sought to carry out an investigative programme,
meaning that tiny paint particles were taken from this area
using a microscope of course.
Embedded in synthetic resin and sanded at a certain angle,
these particles make it possible to show the sequence of layers
– from the primer, to the imprimitura, to the paint layers and the varnish layers and including the overpainting layers.
We are thankful that Professor Christoph Herm
at the Hochschule für Bildende Künste Dresden was able to carry out this examination.”
This is a reflected-light microscope, which can be used to observe polished cross-sections.
We can use either visible light or UV radiation
and by magnifying the image up to one thousand times
we examine the structure of layers in small paint samples.
This image shows, in powerful magnification, the layers,
lying one on top of the other as in a cream pie.
First the primitura, followed by the original layer of paint.
Then, lit up brightly in UV light, we have here two layers of binder
followed by the overpainting
Between the first and the second layer of binder,
there is a layer of dirt
which indicates that the first layer of binder
that is to say, the first layer of varnish
was the painting’s surface for an extended period of time.
The results of this analysis called the previous interpretation of the overpainting into question:
When the work was examined using x-ray technology in 1979
it became known that on the back wall of the room
above the girl’s head,
there was once a large picture showing a naked Cupid
– a god of love – with small wings and a bow in hand.
This finding, which the former museum director
Dr. Annaliese Mayer-Meintschel published in a paper,
became widely known in Vermeer research.
But until recently it was thought
that it was Vermeer himself who painted over the picture in the picture
thus obliterating it.
This assumption made sense insofar
as the painter indeed made a number of changes
to the Dresden painting.
For example, he gently turned the girl
so that she appears in stark profile as we find her today
and he painted over a large wine glass
that was originally depicted in the painting’s lower right-hand corner
essentially making it disappear under the green curtain.
In addition to the scientific findings regarding the layer of overpaint in the background
the painting conservator also made a number of observations.
For example he noticed that the colour of the overpainting is significantly darker
a brownish-grey
and does not correspond to the white wall behind the girl’s back.
It is the unanimous conclusion of the experts involved
that this cannot be the result of a change in colour over the course of time.
Rather, the colour in all likelihood was chosen to match the tone of the varnish
which had yellowed after decades of aging.
What this means is that the painting was several decades old
when the decision was made to paint over the Cupid in the background.
The new findings, including the results of an x-ray fluorescence examination of the work’s entire surface,
were in turn discussed with the expert commission.
In a meeting late in 2017
all participants considered it to have been conclusively demonstrated
that at least several decades stood between the completion of the painting in 1658
and the application of the overpaint,
and thus that the overpainting could not have been done by Vermeer.
The artist died in 1675 at the age of 43.
His painting of the Girl Reading a Letter was only 17 years old at this time.
It is likewise fairly certain
that the overpainting had already been done
when the painting came to Dresden in 1742.
This can be gathered from a letter
written in connection with the acquisition of the work in Dresden.
It contains a short description of the painting,
but without mention of a Cupid in the background.
In December 2017, the museum’s director decided
following the recommendations of the expert committee
in favour of removing the overpaint in a trial strip 1 cm wide
running across the overpainted area in the background.
Taking numerous samples the conservator arrived at the best method for the uncovering:
A so-called mechanical removal using a small scalpel
while looking through a microscope.
It is only in this way that a part of the layer of varnish,
which lies between the original and the layer of overpaint,
can be preserved.
If organic solvents were to be used,
this layer would quickly dissolve.
But because it can be assumed that at least the bottom layer of varnish may have been applied by Vermeer,
its removal should be avoided.
In other words, it is conceivable that a part of Vermeer’s layer of varnish has survived in the Dresden painting,
and this is a finding that is worth preserving.
When the overpaint was removed in the trial strip,
a splendid paint layer was revealed beneath it.
The painting is finely differentiated and was in any case complete
before it was covered by the overpaint.
Even the brush texture still clearly shows!
The results of the trial removal, in other words, were very convincing.
After considering the situation very closely and weighing all risks and potential alternative methods,
it was decided in February 2018 to proceed with the uncovering of the overpainted area in the background.
“This kind of work is very time consuming, very strenuous.
For the painting restorer it is exceptional work, progressing only in very small sections of 1 to 2 square centimetres per day.
You have to take breaks because a lot of concentration is needed in this type of work.”
The restoration of "Girl Reading a Letter at an Open Window" has not yet been completed.
But the spectacular findings pertaining to this major work of Vermeer have inspired us to now
– while the restoration is in progress –
give interested members of the public an insight into the work of the conservator
and a glimpse of the painting as it emerges in its restored state.
 
 
 
 
 
