The 17th century Dutch master Rembrandt van Rijn is justly considered one of the greatest artists of all time. He’s particularly praised for his masterful depiction of light and shadow in his oil paintings, an almost three-dimensional effect achieved with his signature “impasto” technique. The recipes he used to mix his paints were believed to be lost to history. But now a team of Dutch and French scientists has used high-energy X-rays to unlock Rembrandt’s secret recipe, according to a new paper in the journal Angewandte Chemie.
Impasto (translated as “dough” or “mixture”) involves applying paint to the canvas in very thick layers. It’s usually done with oil paint because of the thick consistency and slow drying time, although it’s possible to add acrylic gels as a thickening agent to get a similar effect with acrylics. Rembrandt used it to represent folds in clothing or jewels, among other objects, in his paintings. As David Bressan notes at Forbes, “The layer causes light to reflect in certain ways, giving the painting interesting dark and light contrasts and a three-dimensional effect.”
Like most artists of his era, Rembrandt mixed his own paints, experimenting with different recipes to get different desired effects. Common materials then included lead white pigment (produced via the corrosion of metallic lead) and organic substances like linseed oil. But nobody knew the precise recipe the master used to create the impasto effect.