The need for understanding the rheological behavior of dispersions of soft solid particles has increased, mainly because of their wide range of applications. Many dispersions of practical interest can be represented by a simplified physical model in which the particles are approximated as soft solid-like particles. Starch is commonly used to thicken liquid foods such as sauces, soups, and custards. A microgel particle is a cross-linked polymer particle swollen by a good solvent. Microgel suspensions have a wide range of potential applications in industries involved in coatings, printing, and pharmaceuticals. The suspension exhibits shear-thinning and normal-stress effects in shear flows. In uniaxial elongational flow, the suspension exhibits a strain-thickening effect. The elastic stress is one that would exist in a purely elastic material under the same strain as the particle material. The viscous stress is a Newtonian fluid type stress that is proportional to the rate of strain.