I often paint dark backgrounds. Learning about old techniques, I aspire to approximate those incredible backgrounds of 17th C Dutch painters, using certain pigment mixes and optical tricks. Lately I have been thinking a bit more about further pushing the suggestion of, in particular, space within that darkness. How did someone like Rembrandt create such rich and dark backgrounds and at the same time suggest such optical depth?

A lot goes on in there: backgrounds, called ‘negative space’, serve an important design purpose within the composition and ca be complex – not just a slab of black paint. They are tricky to do well but things make sense when you look at the current knowledge around old techniques. Every time I get the chance to say hi to the old folks in museums, I look at backgrounds as much as at the other elements in their paintings.

As is to be expected, 17th C Dutch painters used several tricks to create their fabulous backgrounds. For example, they used a mix of umber and ultramarine blue which creates a rich dark with a warm or cold appearance depending on the ratio, type of umber, any hints of additional colours as well as the underlying paint. Warm backgrounds were often preferred in order to emphasize those lovely crusty lead white highlights (Rembrandt was particularly good at this). A mixture of umber and ultramarine blue creates a much deeper and richer dark than a black paint can ever achieve.

To enhance the optical illusion of depth a dark pigment was glazed on top once this layer was dry. A glaze is a pigment suspended in a greater quantity of oil (linseed, poppyseed etc) than used for underlying layers of paint, resulting in a transparent paint which can be used to optically mix colours. For example, you can make a yellow look green by painting a blue glaze on top, vs mixing a green paint. This type of optical mixing is a prowerful tool and can be likened to the effect of sunlight seen through a stained glass window. Due to light bouncing about in additional paint layers an optical illusion of depth is created: a rich, deep background. In 17th C Holland the pigment which was commonly used for glazing dark backgrounds was sourced from the peat-rich region around Cologne and Kassel in west Germany.