NF C26-133-1:1994
Specification for pressboard and presspaper for electrical purposes. Part 3 : specifications for individual materials. Sheet 1 : requirements for pressboard, types B.O.1, B.2.1, B.2.3, B.3.1, B.3.3, B.4.1, B.4.3, B.5.1, B.6.1 and B.7.1.