When Mono-Pigment Colours Are Not Mono-Pigment

This also happens. And here we’re talking about fillers and extenders. Generally speaking, all organic pigments will have a certain amount of other components used as a base. They just need to have some particles “to stick to” and create a body of paint. This doesn’t count as a filler as a mineral base is NEEDED for such paints to exist.

However, there is no certain regulation that would place a border between the necessary and extensive use of fillers. That’s why many paints, either organic or inorganic, synthetic or natural,  potentially may contain more than just listed pigments. Common fillers include PW5 (Lithopone), PW18 (chalk), PW19 (Kaoline), PW21 (Barium Sulfate) and others.