What role does an inert pigment play in paint?

An inert pigment serves as a filler or extender in paint formulations, which helps to bulk up the product without significantly altering its color. These pigments are typically non-reactive and do not contribute to the overall hue or shade of the paint. Instead, they help in enhancing the paint's physical properties, such as its viscosity and application characteristics. By acting as a filler, inert pigments can also improve the paint's coverage and overall efficiency during application. This function is crucial for formulations where maintaining a specific color intensity is essential while still achieving the desired volume and texture in the final product.