Most paints contain a material which is known as “pigment”. It’s a natural coloring matter of animal or plant tissue that imparts color to the coating materials (such as paints) or inks, plastics, and rubber.
When shopping for house paint, you may have noticed a term on the side of the can denoting PVC percentage or a pigment volume concentration number. Understanding what it is, how it works, and its importance will help you choose the right paint for the job.
What is Pigment Volume Concentration?
In simplest terms, Pigment Volume Concentration (PVC) describes the amount of pigment found in a paint. This number will tell you how much of the total volume of the paint is made up of the pigment in comparison to the binder.
Represented as a percentage of the paint’s volume occupied by the pigment PVC in paint formulations influences its properties such as color, gloss, opacity, tinting strength, and other characteristics.
When choosing paint, you will want to know the PVC value or “P/B,” pigment-to-binder ratio so you get what you need without exceeding your budget. This number, however, should not be confused with the weight.
To calculate the PVC value yourself you can use this simple formula:
PVC = (Pigment weight / Total paint weight) × 100
So, if you need to calculate the pigment volume concentration (PVC) for a paint sample weighing 250 grams with a pigment content of 10%, it will come out to be:
PVC = (10 / 250) × 100 = 4%
Why it’s important?
Pigment volume concentration (PVC) is a critical parameter in the production of paint, inks, and other colorants. A higher PVC indicates a greater pigment concentration, resulting in more intense colors, improved coverage, higher viscosity, and better durability.
PVC is also valuable for quality control because it helps in monitoring the changes in paint composition with time. However, there are other factors as well that influence paint properties, including the type, size, and cost of pigment particles.
Therefore, the right PVC balance (ratio of pigment and binder) is essential for achieving optimal performance, such as glossiness, permeability, resistance to abrasion, fading, weathering, and chemical exposure.
If there is too much pigment in the coating it may have to be mixed with a binder or used under special circumstances for it to last.
How does it affect paint cost?
The higher the PVC number the more expensive the paint. This is because the pigments are more expensive compared to the binder. This simply means that a cheap paint may have a higher percentage of binder or lower PVC percentage which means you get durable paint, but one that is not as colorful and may be more reflective than desired.
Since some pigments are more expensive, manufacturers might use lower-cost pigments to manage expenses while maintaining desired opacity and coverage. This can be achieved by using smaller particle sizes or blending different types of pigments.
How does it affect the finish and color?
Pigment is a dry powder made from various materials, including minerals, plants, and insects. This powder is mixed with a binder, such as oil or water, to create a pigment paste. The paste is then blended into the paint base and mixed thoroughly to achieve the desired color, texture, and depth.
In general, pigments can be of four different types…
- White pigments (titanium dioxide) – to provide an opaque look to the painted surface.
- Color pigments – made from synthetic chemicals – provide color to the painted surface.
- Inert pigments – used as fillers for altering the basic characteristics of the paint.
- Functional pigments – that help to provide extra performance and protection from UV rays.
Depending on how much lower or higher the pigment volume concentration value is from its optimal range, the more its performance will be affected.
This is why, A PVC value that is too high tends to create a matte finish with more opacity and color strength. Conversely, the greater the percentage of binder, the more it will reflect on the surface creating a highly reflective glossy finish that is far less colorful than desired.
PVC Numbers in Different Types of Paints
It should be noted that the range of PVC value is at its optimal from roughly 30% to 60%. This translates as 40% up to 70% is made up of the binder.
While this may sound counterintuitive in terms of getting the most PVC value for the right color, the truth is that the binder is necessary for the application and duration of the paint drying itself.
What follows are examples of the desired PVC value for the color of Cobalt Blue for various paints.
| Paint Type | PVC Value |
|---|---|
| Acrylic | 20% |
| Oil | 28% |
| Watercolor | 64% |
| Egg Tempera | 72% |
| Casein | 72% |
As you can tell each of the paints listed have different PVC values. Once you get past the optimal range, too much PVC in the paint will lead to a less durable, more permeable, and matte finish that may not be desired.
Are PVC Numbers and CPVC the Same or Different?
PVC and CPVC are two different numbers and are not the same.
Critical pigment volume concentration (or CPVC) is generally defined as a point at which there are enough binders present within a paint to cover each extender particle with a thin layer. This should also be efficient to fill in all the voids between the extender particles.
In general, if the CPVC number is higher than the PVC number, the coating will have more resin than pigments. Due to this excess resin, paint produces a high level of gloss.
It has been seen that as the CPVC is reached, there occur rapid changes in properties which include glossiness, permeability, rusting, tensile strength, blistering properties, etc.
The Bottom Line
PVC and CPVC are the two numbers that describe the properties of a particular paint. The gloss, permeability, contrast ratio, enamel holdout, scrub resistance, and many more properties of the paint can be recognized just by checking these numbers.
While it may not sound important for a homeowner who wants to DIY paint his home, it’s critical for many professionals as it helps to know how the paint will look and feel when done. In most cases, the paint you buy will have a good PVC percentage, but you may be able to get more of what you want at a better price when you understand how it really works.
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Jack Luis is a semi-retired painter who loved painting his clients’ ideas on their walls.
He had worked as a painter for over a decade serving customers in areas such as Charleston, Mount Pleasant, Beaufort, and Georgetown, SC (South Carolina). Today in his free time, he likes to read and write about the newer techniques implemented in his profession. You may read more about him here or get in touch with him here.