Automotive coatings — role of pigments in paint In vehicle paint formulations, adding pigment primarily:

Introduction / Context:
Automotive coatings combine resins, solvents (or water), pigments, and additives to achieve durability and aesthetics. This question checks whether you recognize the primary function of pigments within that system.

Given Data / Assumptions:

• Conventional primer, basecoat, and topcoat layers.
• Pigments include colour pigments and extenders/fillers.
• Application by spray with appropriate reducers and hardeners.

Concept / Approach:
Pigments provide colour (hue), opacity (hiding power), and contribute to film build and surface coverage by filling microscopic surface irregularities. Viscosity is tuned by solvents/reducers and rheology agents. Film hardness primarily depends on resin chemistry and curing (e.g., isocyanate crosslinkers in 2K urethanes), not pigment addition per se.

Step-by-Step Solution:
Identify the function sought: visual appearance and coverage.Map to pigment roles: colour and opacity, plus filling/hiding.Eliminate process control and curing functions assigned to other ingredients.

Verification / Alternative check:
Technical data sheets specify pigment volume concentration (PVC) targets for coverage and durability; changing pigment content shifts hiding power and shade without directly setting hardness.

Why Other Options Are Wrong:
Viscosity control comes from solvents and thinners; hardness from crosslink density and cure—not pigment.

Common Pitfalls:
Over-thinning to chase hiding; ignoring primer-surfacer’s role in filling deep scratches.

Final Answer:
provides colour, opacity, and filling (hiding) power to the paint