Paper is traditionally credited as having been invented by:

Cai Lun (also written Ts'ai Lun), a court official of the Eastern Han dynasty in China, is traditionally credited with inventing paper around 105 CE.

About Cai Lun and paper:

• Cai Lun was a eunuch who served at the court of Emperor He of Han.
• In 105 CE, he presented to the emperor a method of making paper from tree bark, hemp, old rags and fishing nets.
• The materials were soaked, pounded into a pulp, spread on a screen and dried into sheets.
• This paper was much cheaper and lighter than the bamboo strips and silk previously used for writing in China.
• Archaeological finds show that cruder forms of paper existed in China before him, but Cai Lun improved and standardised the process, so he is credited as its inventor.
• Paper is one of the "Four Great Inventions" of ancient China, along with the compass, gunpowder and printing.

Spread of paper-making:

• It spread to Korea and Japan and, after the Battle of Talas (751 CE), to the Islamic world, where Samarkand and Baghdad became centres of paper production.
• It reached Europe through Muslim Spain in the 11th and 12th centuries.
• Paper became common in India from about the 13th century, during the Delhi Sultanate.

Other inventions:

• Movable type printing: Bi Sheng (China, about 1040 CE), using clay type.
• Printing press with metal movable type: Johannes Gutenberg (Germany, about 1440); the Gutenberg Bible (about 1455).
• Seismoscope: Zhang Heng (China, 132 CE).
• The first printing press in India was set up by Portuguese Jesuits in Goa in 1556.

Paper Day:

National Paper Day is observed in India on 1 August.

Why not the other options?

• ✗Bi Sheng invented movable type printing in China.
• ✗Johannes Gutenberg invented the metal movable-type printing press in Europe.
• ✗Zhang Heng invented the seismoscope.