Painters are a sort of user interface delegate for drawing foregrounds and backgrounds. SwingX includes some built-in painters:
CompoundPainter, as its name indicates, is a collection of other Painters. Order is important. CompoundPainters build from back to front. Here is an example of a CompoundPainter:
AlphaPainter is a CompoundPainter as well, adding an alpha value to a collection of Painters.