Footballs used in association football or soccer have a circumference of 27 to 28 inches. It weighs around 410 to 450 grams and is inflated to a pressure of 60 to 10 kPa. Footballs are usually covered with leather. But, today different types of materials are used to cover it. The footballs used in modern day games are stitched from 32 panels of leather or plastic. Leather and plastic used in football should have waterproof property. It is also stitched from 2 regular pentagons and 20 regular hexagons. Truncated icosahedron is the name given to the 32 panel. It is quite similar to the polyhedron but is more spherical. The spherical shape is due to the pressure of the air inside the football.
Footballs have a long history. It is the product of the pleasure that we get by kicking something. Earlier footballs were anything that was suitable for kicking. Stitched plant leaves filled with soft materials, skulls, animal bladders and similar objects were used as footballs. Ancient cultures around the world is said to have used objects similar to present day football. Pig bladders were used as football during the medieval period. Rubber was used during the 18th century. The first vulcanized football was designed and built in 1855. Inflatable rubber bladders were developed in 1862. Soon the English Football Association brought in the rules regarding footballs which were changed several times. The 20th century saw the evolution of football into its present day characteristics. High tech designs and materials are used in the present day footballs. กฎการเล่นพนันบอล
The design of black pentagon and white hexagon in 32 panel was the official ball of 1970 Mexico world cup. It is the most widely accepted design mainly due to its visibility. But several companies have now brought out premium branded balls with elaborate designs. The standard football size is 5. The other sizes that are available are 4 and 3. In indoor competitions the size of football used is 4. The material used in the football varies according to the manufacturer. Most of the important brands still manufacture leather football, which is popular with football fans. Attractive logos and designs feature in most of the latest footballs.