Nanodiamonds are tiny diamond particles that usually measure mere millionths of a millimeter. They are extremely hard, stable and heat-resistant and highly adaptable for various purposes in medicine, new materials, catalysis and energy technology. By compressing plastic with lasers, researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and the University of Rostock are now able to systematically produce high-purity, ultra-small diamonds with a narrow size distribution. This is impossible to achieve with conventional methods such as explosions. As a scalable technology, laser compression offers great potential for improved, clean and sustainable production of ultra-small nanodiamonds.