Auer von Welsbach then started work on development of metal-filament mantles, first with platinum wiring, and then osmium. Osmium is very difficult to work with, but he developed a new method, which mixed osmium oxide powder with rubber or sugar into a paste, which is then squeezed through a nozzle and fired. The paste burns away, leaving a fine wire of osmium.
Although originally intended to be a new mantle, it was during this period that electricity was being introduced into the market, and he started experimenting with ways to use the filaments as a replacement for the electric arc light. He worked on this until finally developing a workable technique in 1898 and started a new factory to produce his Auer-Oslight, which he introduced commercially in 1902. The metal-filament light bulb was a huge improvement on the existing carbon-filament designs, lasting much longer, using about half the electricity for the same amount of light, and being much more robust.