CTC tea actually refers to a method of processing black tea, named Cutting, Tearing and Curling.
CTC BOP
Black BOP is the CTC biggest grade. With blackish appearance, good smelling and heavy leaves, CTC BOP Black tea is an attractive product.
BP
Black BP is the second biggest grade CTC which is smaller than CTC BOP. With blackish appearance, good smelling and heavy leaves, CTC BOP Black tea is an attractive product.
PF
Black PF is the third biggest grade CTC which is smaller than CTC BP. CTC PF is often used in producing filter tea bags.
PD
Black PD is the smallest CTC grade which is often used in producing filter tea bags.