Cylindrical screen having aperatures with geometric centers defined by arrays of equilateral triangles

摘要

An improved cylindrical printing screen having aperatures located such that their geometric centers define an array of equilateral triangles each having one side which defines a 15 degree angle with respect to the circumferential direction, another side which defines a 15 degree angle with respect to the longitudinal direction and a third side which defines a 45 degrees angle with respect to both the circumferential and longitudinal directions of the cylinder is disclosed.