This sheet of IEC 60819-3 specifies requirements for two types of filled glass paper designated:
P-FG type 1: high inorganic content paper with maximum organic content 15 %;
P-FG type 2: medium inorganic content paper with maximum organic content 25 %.
IEC 60819-3-1:2001 history
2001IEC 60819-3-1:2001 Non-cellulosic papers for electrical purposes - Part 3: Specifications for individual materials; Sheet 1: Filled glass paper