Basics of technical research


A close look to better understand Vermeer's painting technique

In this story we want to demonstrate how technical research on two works by Vermeer from the National Gallery, London, can help us to understand his painting technique.

This type of investigation is a collaboration between the conservation, curatorial and scientific departments at the National Gallery and provides information about the materials Vermeer used and how he combined them in different ways. The research can also indicate when materials have changed over time, altering the appearance of the paintings.

Paint application
We can examine the paint surface under magnification, observing details that are difficult or impossible to see with the naked eye.

For example, in a Young Woman seated at a Virginal, the tiny dashes of colour Vermeer used to reproduce the scintillating effects of light playing over textured surfaces can be observed.

We can also begin to appreciate Vermeer’s loose brushwork and the ways in which he exploited paints of varying consistency.

For example, we can see the fluid impasto paint used for the silky sleeve in a Young Woman Standing at a Virginal

or the thick paint employed for the tiles at the base of the wall in a Young Woman Seated at a Virginal.

Instead of painting the tile edges, Vermeer made indentations into the wet paint to reveal a dark under-layer.

Brush bristles
With the microscope we can even see brush bristles unintentionally embedded in the surface of the original paint; in this image, there is a bristle just below the head of the final ‘r’ of Vermeer’s signature!

At this time brushes were made with bunches of bristles tied to a handle, so these may have worked themselves out of an old, deteriorated brush, or perhaps were left as a consequence of the vigorous way in which Vermeer painted broad background areas.

There is nothing particularly unusual about the pigments Vermeer used – all of which were common to the 17th century painter’s palette – but the distinctive colours in his paintings are often the result of these pigments being combined in highly unusual ways.

The only blue pigment used by Vermeer in both National Gallery paintings is natural ultramarine. This pigment, extracted from finely ground lapis lazuli which came from Afghanistan, was extremely expensive and many artists only used it for bright blue areas so they could derive maximum effect from its intense colour.

Vermeer has used ultramarine alone (or mixed with white) in many areas, for example, in the upholstery of the chair...

... for the woman’s bodice and for the sky of the landscape pictures hanging on the wall in a Young Woman Standing at a Virginal.

Unusual combinations (dress)
However, Vermeer has also used ultramarine in mixtures to create many of his colours (even browns in some cases)! While other artists would have chosen to use a different, less costly, blue pigment in such mixtures, it is Vermeer’s liberal use of ultramarine that leads to such a unique colour palette. It also helps to achieve an integrated harmony of colour in his paintings.

Vermeer often combined ultramarine with a green earth pigment to form a range of blue-greens and greenish-blues. This is the case for the dress of a Young Woman seated at a Virginal, which has a distinctive blue-green colour.

We can actually see the pigment mixture by taking a tiny sample of paint from the skirt and mounting it in polyester resin to produce a paint cross-section.

This sample is very small, so must be examined under a microscope. The scale bar on the left hand side is 20 microns, or about a quarter of the diameter of a human hair, so it really is a very small sample!

Using a microscope, we can see that the intense blue pigment particles of ultramarine are mixed with the particles of green earth (and a few tiny particles of red earth) in the same paint layer.

The colour and shape of pigment particles can be quite characteristic, but their identification is usually confirmed using another piece of equipment; a scanning electron microscope fitted with a special detector which can tell us exactly what chemical elements are present in each particle within the sample.

Unusual layer structure (flesh)
Another unusual feature of both National Gallery paintings is Vermeer’s use of a green earth pigment in the flesh tones of the figures.

Green earth was frequently employed in Italy in the fourteenth century as an under-paint for flesh, but in these paintings by Vermeer he applies green earth over pink and other flesh colours to produce his very distinctive cool shadows.

This can be observed in A Young Woman seated at a Virginal, for example, where paint containing green earth has been used for shading in the flesh tones around the eye.

Alterations (ultramarine)
But what we see in Vermeer’s paintings today is not always what the artist originally intended. The vibrant blue-coloured ultramarine may have been an expensive pigment, but it is not without problems. Over time, ultramarine-containing paint passages can acquire a blanched appearance and become lighter in tone.

A paint sample taken from a particularly deteriorated and blanched area in the blue upholstery of the chair in a Young Woman standing at a Virginal was made into a cross-section.

This clearly shows a pale band at the top of the layer where the paint has altered.

The exact mechanism of this degradation process is complex and not fully understood, though there is some indication that ultramarine may interact in some way with an oil binder.

The deterioration is often most prevalent in areas where the blue was used alone or with only a small amount of added white pigment.

As these dark areas become lighter, the modelling (balance of light and shade) in the painting can be affected, becoming less obvious.

Alterations (soaps)
A granular texture in certain areas, caused by lumpy particles protruding through the paint surface, has long been noticed. In the past it had been suggested that Vermeer had added something to his paint to achieve this effect.

These protrusions can be seen in a Young Woman Standing at a Virginal, for example, in the painting-within-the-painting.

Vermeer has used thick dashes and dots of bright yellow to render the play of light on its gilt frame, but the beige spots visible in the brownish-yellow ochre base colour are small protrusions of disrupted paint and are not deliberate.

Analysis has shown that these have formed as a result of chemical reactions between the oil binder and lead-containing pigments such as lead-tin yellow or red lead and are therefore an unintended consequence of the materials used by Vermeer which would not have been present when he was painting.

In fact, similar protrusions can be observed on many paintings by a variety of artists.


If you would like to learn more about Vermeer and his materials or would like to find out more about the work of the scientific department, please visit the National Gallery website, where all of the topics mentioned here are explored in greater depth.

Vermeer and Technique

Credits: Story

Created in collaboration with the National Gallery
This exhibition is part of the Google Vermeer Project.

Vermeer and Technique

Credits: All media
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