A football (also known as football ball, soccer ball, or association football ball specifically in the United Kingdom) is the ball used in the sport of association football. The name of the ball varies according to whether the sport is called "football", "soccer", or "association football". The ball's spherical shape, as well as its size, weight, and material composition, are specified by Law 2 of the Laws of the Game maintained by the International Football Association Board. Additional, more stringent standards are specified by FIFA and subordinate governing bodies for the balls used in the competitions they sanction. Early footballs began as animal bladders or stomachs that would easily fall apart if kicked too much. Improvements became possible in the 19th century with the introduction of rubber and discoveries of vulcanization by Charles Goodyear. The modern 32-panel ball design was developed in 1962 by Eigil Nielsen, and technological research continues to develop footballs with improved performance. The 32-panel ball design was soon joined by 24-panel balls as well as 42-panel balls, both of which improved on performance prior to 2007. A black-and-white patterned spherical truncated icosahedron design, brought to prominence by the Adidas Telstar, has become a symbol of the sport. Many different designs of balls exist, varying both in appearance and physical characteristics. History First years of football codes In the year 1863, the first specifications for footballs were set by the Football Association. Previous to this, footballs were made out of inflated animal bladder, with later leather coverings to help footballs maintain their shapes. In 1872 the specifications were revised, and have been kept essentially unchanged by the International Football Association Board. Differences in footballs made since this rule came into effect have been with the material used to create them. Footballs have dramatically changed over time. During medieval times balls were normally made from an outer shell of leather filled with cork shavings. Another method of creating a ball was using animal bladders to make it inflatable inside. However, these two styles of footballs were easy to puncture and were inadequate for kicking. It was not until the 19th century that footballs developed a more modern appearance. Vulcanization In 1838, Charles Goodyear introduced vulcanized rubber, which dramatically improved football. Vulcanization is the treatment of rubber to give it certain qualities such as strength, elasticity, and resistance to solvents. Vulcanization of rubber also helps the football resist moderate