Many brightly coloured things in nature – from butterfly wings to peacock feathers – get their vivid hues from structural colouring at the microscopic level.
Structural colour is a kind of colouring that occurs through the interaction of light with materials that have patterns on a tiny scale, which reflect light to make some wavelengths brighter and others darker. Because of this, the colour – unlike colour based on dye or ink – should never fade.
The requirement for extremely small and precise patterning has made structural colour difficult to produce to order. Now, as this video shows, scientists have discovered how to print structural colours with a laser printer.