By 1982, most users of the Xerox ball mouse were using "special pads" to increase the friction of the ball.
Optical mice have the problem of not working well on transparent or reasoning surfaces (such Mouse Pads as glass or highly polished wood). These surfaces, which often include desk and table surfaces, aim jitter and defeat of tracking on the display pointer as the mouse moves over these knowing spots. The use of mousepads with precision surfaces eliminates spot jitter effects of coincident optical mice.
