Fig. 2. Schematic illustration of volume available (blue) and volume excluded (pink and black) to the center of a (A,C) small and (B,D) large spherical molecule added to a solution containing a approximately 30% volume fraction of large spherical molecules (A,B) and the interior of a pore shown in (square) cross-section (C,D). Reproduced from Minton (Minton, 2001a).