How did Vermeer make the paint that was used in the Girl with a Pearl Earring? Like most 17th century Dutch artists, he used oil paint. Paint is made from pigments (coloured powders) mixed with a binding medium to make a thick, soft paste. The next few blog entries will be devoted to the pigments that Vermeer used to make different colours, and where they came from, but first, let’s hear about his oil.
Linseed oil was identified in the Girlby analysing samples using Gas Chromatography-Mass Spectrometry (GC-MS). Remarkably, GC-MS found that the oil in the background also contains a tiny amount of rapeseed oil. We don’t yet know much about the use of rapeseed oil in paintings, since it isn’t mentioned in historical recipes. It’s unlikely that Vermeer added this himself. Maybe the rapeseed was a contamination of linseed oil, as windmills were probably used to press oil from different sources.
In 17th century Netherlands, linseeds were commonly pressed using a windmill. At the Dutch oil mill Het Pink, you can see this process for yourself:
It seems that Vermeer bought – or maybe even made – a specific type of oil that allowed him to control how thick his paint was, and how fast it dried. Analysis with GC-MS showed that the oil was slightly heat-bodied. Heating oil to a high temperature (around 300°C, usually with added dryers) would have changed its painting properties, making it smoother, glossier, easier to paint with, and perhaps faster drying.
Drying
Linseed oil – unlike olive oil or vegetable oil – is a ‘drying oil’, meaning that it can set to form a stiff, rubbery film. When it is used to make oil paint, it dries at different rates depending on which pigment(s) are chosen.
If you’ve ever made an oil painting, you’ll know that it doesn’t dry right away. You can move the paint around with your brush for minutes, or even hours after you’ve applied it. The slow drying speed of oil paint allowed Vermeer to blend colours together in the Girl, and to manipulate his paint after he applied it. To achieve the subtle blending from light to shadow, for example the translucent skin on the edge of her cheek, he used a soft dry brush to blend the wet paint after he applied it.
The slow drying speed of oil paint allowed Vermeer to blend colours together, and to manipulate his paint after he applied it. On the other hand, without the help of dryers, some coloured paints would take forever to harden. This would have made it impossible to layer one colour on top of another. Oil paints dry at different rates depending on which pigment(s) are chosen. In his 17th-century ‘painter’s manual,’ Theodore De Mayerne listed the drying times of different pigments, including: umber (2-3 hours), lakes (5-6 days), and that black paints will never dry unless they had been modified with a dryer. Samples from the Girl were analysed using SEM-EDX, which detected lead in some of his dark paints.
Vermeer let some layers dry thoroughly before he applied more paint on top. Most cross-sections show a distinct separation between layers of paint.
Paint tubes weren’t patented until the 19th century. In Vermeer’s time, small quantities of prepared paint were kept in covered pots, or in animal bladders. When an artist was ready to use the paint, he could prick the bladder with a needle, and squeeze out a small amount onto his palette.
