When production first began on codices around the end of 4^th century, each page usually had a three-column layout. In the 9^th century and thereafter, the double-column layout became popular, and it was often used for printing incunabula, including the 42-line Bible. In medieval manuscripts concerning laws, explanatory notes were positioned around the text of the laws. In the same way, the type was set so that notes were arranged to surround the text in incunabula.