Halftone screen angles With the exception of FM (stochastic screening), all screens consist of dots arranged in a regular pattern or matrix. The vertical and horizontal distance between successive dot centers is constant and is a function of the screen frequency. When the screen is aligned parallel to the paper edges, the screen angle is said to be 0° or 90°. The rotation angle away from the vertical axis is known as the screen angle. The screen can only be rotated up to 90° before it repeats itself. For example, a screen rotated 15° is at the same angle as 105°, 195°, and 285°.