Wouldn't simply changing the page colour to some solid colour (white if it isn't already set, full opacity of any other colour set) fix this, rather than a "backstop rectangle"? Obviously then you wouldn't have to resize anything.
Wouldn't simply changing the page colour to some solid colour (white if it isn't already set, full opacity of any other colour set) fix this, rather than a "backstop rectangle"? Obviously then you wouldn't have to resize anything.