What is the term for the measure of a paint’s resistance to flow?

The term that describes a paint's resistance to flow is viscosity. Viscosity is a fundamental property of liquids and is indicative of how thick or thin a fluid is. In the context of paint, viscosity affects how easily the paint can be applied and spread over a surface. A higher viscosity means the paint is thicker and flows more slowly, while lower viscosity indicates a thinner paint that flows more readily.

Understanding viscosity is crucial for paint formulation and application. For example, high-viscosity paints may be used for specific applications where a thicker coating is desirable, while low-viscosity paints are often preferred for smooth application and achieving a fine finish. Additionally, the viscosity of paint can change with temperature and shear rates during application, making it an essential parameter in both the manufacturing and usage of paint products.

The other terms, while related to fluid properties, denote different characteristics. Density pertains to the mass per unit volume of the paint, rheology describes the study of the flow and deformation of materials, and thixotropy refers to the property of certain materials that become less viscous when agitated or shaken but regain their viscosity when at rest.