Load or create you mask (Darker areas will allow more
color through)
For this tutorial I created another window the same size
as my graphic then filled it with a sunburst gradient
using the fill tool.
Select MASK>NEW>FROM IMAGE
(Source Window This Window, Create mask from Source luminance)
Make your original graphic the active window by
clicking on it's title bar
Select EDIT>COPY
Make your mask the active window by clicking on it's
title bar.
