The FIFA World Cup pictured with 20 soccer balls timeline.
WorldWide Tech & Science. Francisco De Jesùs.
Despite the source information is in Spanish, you can see in the slides of each soccer ball, how the balls were made through the time ,every 4 years to be specific, with a different material, hand made at the beginning, leather colors, some times with label named, to finally Adidas from 1970 started to make all the balls, for every World Cup, until now , with the latest Brazuca model for the upcoming 2014 event in Brazil
Source: DiarioElComercio Ecuador