Some colours were made from very strange things
A PIGMENT is the coloured powder at the heart of any paint, and for most of history each one had to be dug up, ground or cooked. Some had alarming sources. Mummy brown, a rich shadowy colour sold into the twentieth century, really was made from ground-up ancient Egyptian mummies. When the painter Edward Burne-Jones found out what was in his tube, he is said to have held a small funeral and buried it in his garden.
Others were dangerous to the painter. Lead white was the standard white for centuries and slowly poisoned people who used it. A bright green invented in the 1770s got its colour from arsenic, and was used in wallpaper as well as paint. Modern artist's paints are made from safer, factory-made pigments, which is a large part of why a child's paint set costs so little.
Paint and light mix differently
Every child learns that yellow and blue make green, and it works because pigments subtract colour: each one soaks up some parts of light and reflects the rest, so MIXING two leaves less light reflected and a darker colour. Mix too many and you get muddy brown. Printers use cyan, magenta and yellow for the same reason.
Light itself works the other way. On a screen, red and green light added together make yellow, and all three primary colours of light together make white. Our light and sound page explains why. A painter's PALETTE is usually laid out with colours in the same order every time, so the hand knows where to go without looking.
Oils, watercolours and everything between
OILS dry slowly, over days or even weeks, so colours can be blended on the CANVAS and a painting reworked. WATERCOLOR works the other way round: it is transparent, so painters start with the lightest areas and build darker layers on top, and the white is simply the paper left bare. GOUACHE is watercolour made opaque, so it covers what is underneath.
ACRYLIC paint only became widely available in the 1950s. It dries in minutes, cleans up with water while wet, and turns plastic-hard once dry. A PRIMER, often a chalky white called gesso, is brushed onto a canvas first so paint sits on top instead of soaking in. A PASTEL is pure pigment pressed into a stick, so pastel drawings smudge easily and are often sprayed with a fixative.
The Night Watch was never set at night
Rembrandt's great group PORTRAIT of 1642 shows a company of Amsterdam citizen soldiers setting out in daylight. Over the next century its VARNISH darkened so badly that people assumed it was a night scene, and the nickname stuck. Varnish protects a painting but turns yellow and brown with age, and cleaning it off is how restorers reveal the bright colours old masters actually used.
The rest of the grid is the working kit: the EASEL and BRUSH, the SMOCK that keeps paint off clothes, the STUDIO, and the steps of making a picture — the SKETCH and OUTLINE, SHADING to show light falling on a shape, and TEXTURE built up with thick paint. There are big formats too: the LANDSCAPE, the MURAL painted straight onto a wall, the FRESCO painted into wet plaster, and the STENCIL, which lets the same design be repeated exactly.