This specification applies to natural-coloured material and specifies requirements for two types of thermosetting synthetic-resin bonded-paper sheets, as defined below, for use at frequencies up to and including 30 Mc/s. Limits are specified for sheets from 1/64 in. to 1/4 in. thick (nominal).

The punching test specified in Clause 10a applies to sheets up to and including 3/32 in. thick (nominal) only, and the test specified in Clause 10b to sheets up to and including 1/8 in. thick (nominal) only.