When viewing the matte, use the Transparency field to vary the matte display transparency from 0% (completely transparent) to 100% (fully opaque). Press Alt+T or click Transparency in the Setup menu to toggle between the last set value and 100%.
(a) Transparency field
Note: The transparency value only affects the display of the matte. It does not affect how the matte is used.
(a) Invert Lock button (b) Transparency button