  Paint marbling refers to techniques for creating intricate designs in colored
paints floating on a liquid surface. If the marbling motions are executed
slowly, then this layer of paints can be modeled as a two-dimensional
incompressible Newtonian fluid.
  In this highly constrained model many marbling techniques can be exactly
represented by closed form homeomorphisms. Homeomorphisms can be composed and
compute the composite mapping at any resolution. Computing homeomorphisms
directly is orders of magnitude faster than finite-element methods in solving
paint marbling flows.
  Most marbling patterns involve drawing rakes from one side of the tank to the
other; and these can be modeled by exact closed form homeomorphisms. But
pictorial designs for flowers and animals use short strokes of a single stylus;
presented is an exact velocity field for Oseen fluid flow and its application
to creating short stroke marbling homeomorphisms.
