USA Bishop Nocturnal series --milky white , this ink is cooperativly made by "the father of black and grey" Jack Rudy and Franco originating Bishop Rotary INC. It is a unique ink. especially used for mixing . You can do all the black-and-grey style works if you use it with all the other nocturnal series inks . The nocturnal series inks are in small and medimum-sized particle, it is a water-based ink with high fludity. There are tonly 3 ingredients : organic pigments , ethyl alcohol, sterile water,It is more fluent and easier to mixed with other brands inks because of there is no chemical solvent.