Angling 4-color separation
Angling of 4-color half tone separations
In repro techniques, suitable angling eliminates the moiré effect between the half-tone of the individual component colors. The angle should not be selected arbitrarily. Half-tone angling is often given in two different ways:
Within 90° for rulings with two axes of symmetry (e.g. round dots)
Within 180° for rulings with one axis of symmetry (e.g. elliptical dots)
Strong colors like CYAN, MAGENTA and BLACK must always be at an angle of 30° from each other. This minimises visible moiré patterns due to the interplay of the raster rulings. YELLOW, beeing a weaker color, can be set at a 15° angle apart from a darker color.