Light-bulb, filament carbon E.S. cap, Edison. Label on glass says 'Edisons Patent'.

Filaments made from paper were not entirely satisfactory. Filaments made from bamboo proved to be much better and were used in all Edison lamps for a number of years.

Edison tried many different materials for his filaments. The first sample of bamboo reputedly came from a palm-leaf fan found in the laboratory. Edison sent explorers all over the world to look for the best type of bamboo, but a supply of a suitable type was easily arranged from Japan. It was probably in the spring of 1880 that Edison first tried bamboo, though in June 1880 he was still trying new materials.