Most people have come into contact with paint at some point in their life. Many of us have painted our homes (inside and out) and some have even painted as a form of artistic expression. It is probably a safe assumption that although we know what paint is, and how to use it, most people do not even know what paint is made of. Sure, we know it’s a combination of chemicals (based on the fumes) and that at some point lead may have been used but that’s where our knowledge of paint ends.
In order to understand paint quality, choice, and application, it’s first important to understand what paint is made of…
Paint is made up of 3-4 main ingredients:
Pigment is what gives paint its color and texture. Dangerous pigments such as lead and asbestos used to be common, but now are mostly outlawed. Pigments are ground up and applied to the resin/binder. Cheaper pigment materials (such as clay) cannot be ground as finely as the better pigments can, and you can actually tell whether paint is good or not by rubbing it between the tips of your thumb and index finger. If it feels gritty, it probably contains either a cheap pigment or lot of cheap filler. This kind of paint will not normally last as long as other high-end paints.
Binder (or Resin) is what holds everything together (hence the name). The binder determines many of the necessary film properties such as adhesion, gloss level, hardness, abrasion resistance, flexibility, speed of drying and durability.
A solvent is the liquid that carries the solid components of paint. It is what allows the paint to be “wet” and adhere to the surface being painted.
The solvent type effects the flow of the paint after it has been applied as well as how the paint dries. Once paint has been applied, the solvent evaporates and leaves a dry film on the surface.
As the name suggests, Additives are components added to the paint to improve different properties to the wet mix or the dry film. Types of additives include Wetting Agents, Anti-Settling Agents, Anti-Skinning Agents, Drying/Curing Agents, Stabilizers, Anti-Marring Agents, and Anti-Mold Agents. If a paint claims to have special features such as “Quick Drying”, “Mold Resistant”, or “Scuff Resistant” it is usually a result of the additives put into the paint.
There you have the basic components of paint. These 4 main ingredient types can be specialized and tailored to create different paints for all sorts of uses such as interior, exteriors, auto, marine, industrial, agricultural, etc.
So the next time you walk into a home improvement store and wander down the paint aisles, take a look at all the types of paints available and remember that they are all made up of 4 main ingredients: Pigment, Binder, Solvent & Additives.