Sets the opacity of the menu items in currently selected level. The value is the percentage 0-100 with 0% for completely transparent (invisible) menu blocks and 100% for normal (opaque) display.

The opacity should not be used to configure the menu with normal text and transparent background. Instead transparent background color should be selected in the styles editor.

The opacity is supported by a limited number of the browsers. Where not supported the menu items will be displayed with default (opaque) setting.