Thanks again, Hoofdcommissaris. Certainly subsurface scattering would be one way to model the effect Im after -- though, I think, an unnecessarily complicated way. As for other methods, you probably hit the target exactly when you said, Carrara does not handle its objects as solids. The distance fog option works according to the path length light travels between an object and the camera. If a light ray travels twice a given distance through the fog, it is dimmed by twice the amount. But there just doesnt seem to be any way to create a shader in Carrara that will do this within the boundaries of an object, attenuating the light passing through in proportion to the distance the light travels through an object of varying thickness. Sigh.