Why do some paints require many, many coats to achieve the final colour?
- Paints are made out of a mixture of resins, solvents, pigments and other trace additives.
- It is the amount, and type, of pigments that gives a base paint hiding power.
- Generally, pigments in paint are a white powder that get dispersed into the liquid mixture, and can include TiO2, opaque polymers, Zinc Oxide, chalks, clays and calcium carbonate.
- The whiter the powder pigments used, and the finer they are ground before dispersion, the more hiding power or opacity they will provide.
- When paints are then tinted, it is the pigment concentration of the colorants used that give them better hiding powder.
- Additionally, the amount of resins, or solids, in the paint, the thicker a film it will apply to surface being painted, which also increases hide.