 The light material of silk was sometimes used as a recording medium, but was normally too expensive to consider.The Han dynasty Chinese court official Cai Lun (c. 50–121 CE) is credited as the inventor of a method of papermaking (inspired by wasps and bees) using rags and other plant fibers in 105 CE.However, the discovery of specimens bearing written Chinese characters in 2006 at Fangmatan in north-east China's Gansu Province suggests that paper was in use by the ancient Chinese military more than 100 years before Cai, in 8 BCE, and possibly much earlier as the map fragment found at the Fangmatan tomb site dates from the early 2nd century BCE.