This presentation on rheology reviews the basic principles of rheology including its definition and its influencers – chemical structure, morphology, and environmental conditions.  The impact by various deformation forces including compression, tension, torque and, particularly, shear will be reviewed to demonstrate the resulting flow profiles as a function of shear and time.  The chemistry and ancestry of current rheological agents will help clarify the appropriate selection of products for various formulation types including waterborne, solventborne, aliphatic, aromatic, and polar systems.