Do you know why the screen angles in 4 color process printing are so important? The least visible color, yellow, is placed at the most visible angle 0º. Then the most visible color, black, is placed at 45°. The cyan and magenta are then placed between these two. Cyan at 15° and magenta at 75º. These angles are tried and tested standards that produce the most ideal printed images and also create the rossette pattern.