Syntax

[the] roundWidth of <buttonOrGraphic>

if the roundWidth of button 1 is unset then ...
set the roundWidth of button "Quit" to 4

Explanation

The roundWidth property lets you control the corner-roundness of buttons with style roundRect. The roundWidth is the radius of the little circle that makes up the rectangle’s corner at its widest.

Illustration of what roundWidth and roundHeight are

See Also