Over the last twenty years, many studies have been made of radiative transfer in scaling Cloud fields, the vast majority of which have been limited to numerical studies in clouds with relatively small optical thickness. An exception to this was the development of a formalism for treating single scattering in optically thick but conservative multifractal clouds without significant holes. In part I of this paper we show how these results can be extended to general "universal" multifractal clouds dominated by low density "Levy holes". In part II, we demonstrate how the analytic single scattering results can be generalized to multiple scattering including the case of very thick clouds as well as to realistic nonconservative clouds. (C) 2009 Elsevier B.V. All rights reserved.