A process for preparing a black colorant, preferably a black pigment, characterized in that a compound of the Formula is reacted with a compound of the Formula in a molar ratio of 1:2, in the presence of a catalyst which in water at 25\xb0 C. The captured ammonia may be recovered by heating the aqueous ammonium phosphate, which then may be recycled. The junction and leads are arranged in a plane and the junction is configured to exhibit quantum confinement in a direction perpendicular to the plane. The cover includes a pair of lateral sides having blocking walls being bent downwardly and distant to the sidewalls of the stiffener.