Ever bought a fake Rolex or counterfeit Chopard? Probably not, but recent work by EPFL based start-up Nanoga may reduce the chances even further. The team has developed a deposition and photolithographic technique to put a nanoscopic watermark onto glass. The nano-watermark being visible under ultraviolet light. Initially developed for high-end sapphire crystal watches, the company has patented a system of photonic watermarks for glass, ceramic and metal.