The Anatomy of Paint: Pigment and Binder

dry pigments in powder form

"For the twentieth-century painter, who normally regards paint as a pasty substance of a certain color that can be squeezed from a tube, it is hard to imagine that to artists not only of the fifteenth and sixteenth centuries, but also of the seventeenth, the eighteenth and the first half of the nineteenth century, each pigment presented its own inherent   possibilities and limitations. Some pigments could not be worked-up with oil; some pigments could only be safely mixed with one or two other pigments; some pigments could only be used transparently and yet others only opaquely. Other properties, too, such as color permanence, workability, drying qualities, and so on, could differ so strongly from one pigment to another that it was normal to use a given pigment in pure form or mixed with a limited number of other pigments when modifying  tone and color."¹ In fact, many mixtures of paint in Vermeer's painting  contain only two or three different pigments.

Artist's paint consists primarily of two components: pigment and binder. In order to produce paint, pigment and binder are ground into a stiff paste which must have three requirements: it must be brushable, it must adhere permanently to the support's surface and it must not alter significantly in time. In the Netherlands canvas and panel were preferred as supports but copper was also used as support. Through chemical analysis, it would appear that Vermeer employed  the same materials to produce his paints as those employed by his contemporaries.

Pigment

a piece of unprocessed lapis lazuli

Pigment is the actual coloring substance of paint. It is usually of mineral or organic origin although some pigments, such as the all important lead-white, were artificially produced. The pigment, after being first separated from gross impurities, is thoroughly cleansed. It usually presents itself in powdered form. Some pigments possess little or no bulk and must be fixed on a more solid, but at the same time transparent, substance or base, as it is sometimes called. Alum or clay are used for this purpose. These pigments, which are called lakes are unusually very transparent.