... is 7-11mm. Most of the darjeeling tea is OP type. BOP: Same leaves as OP, but they are ... BOPF: Smaller than BOP. About 1-2 mm. Often used for tea bags. D( dust ): Powdery tea, made with CTC ... price. In other countries, black tea is classified as SFTGFOP, FOP, OP, FBOP, BOP, BOPF, BOPD, OP1, etc. ... price. In other countries, black tea is classified as SFTGFOP, FOP, OP, FBOP, BOP, BOPF, BOPD, OP1, etc. ...