INTRODUCTION To be able to offer a wide range of color for coating, different type of pigment are used. To insure a good cohesion between the different components and so optimize the properties of the coating in term of viscosity, polymers are added to the suspension. The aim of the polymer is to insure a good thixotropy (viscous at rest and fluid under stress) and insure a good adhesion to the support. The concentration of polymer directly affects the stability and the viscosity of the formulations, consequently by adjusting the concentration, the thixotropy and the stability can be optimized. The Turbiscan technology enables to monitor the stability of these dispersions as a function of the polymer concentration.