Tells fvwm the maximum size window with which opaque window movement should be used. The percentage is percent of the total screen area (may be greater than 100). With

OpaqueMoveSize 0

all windows are moved using the traditional rubber-band outline. With

OpaqueMoveSize unlimited

or if a negative percentage is given all windows are moved as solid windows. The default is

OpaqueMoveSize 5

which allows small windows to be moved in an opaque manner but large windows are moved as rubber-bands. If percentage is omitted or invalid the default value is set. To resize windows in an opaque manner you can use the ResizeOpaque style. See the Style command.