We have discovered a new WO3 polymorph as a a 2D nanomaterial, through aqueous chemistry at low temperature. This material shows mpressive electrochromic properties. Congrats to Julie and Binghua for their great work, and thanks to collaborators from SOLVAY, INSP Paris, IPCM Paris, IRCP Paris, UC Madrid and UCCS Lille for bringing their own bricks to this nice assembly. Check the paper and the story of the discovery there and on the CNRS web site.