Colour printing reaches its ultimate resolution

Images made up of metal-nanostructure pixels could be used for security or optical data storage.

The highest possible resolution images — about 100,000 dots per inch — have been achieved, and in full-colour, with a printing method that uses tiny pillars a few tens of nanometres tall. The method, described today in Nature Nanotechnology¹, could be used to print tiny watermarks or secret messages for security purposes, and to make high-density data-storage discs.