Värvipigment

Värvipigment is a substance that imparts color to other materials by selective absorption and reflection of light. These are typically in finely divided solid form. Pigments are insoluble in the medium in which they are applied, unlike dyes which are soluble. This insolubility is a key characteristic distinguishing pigments from dyes.

Pigments can be organic or inorganic. Inorganic pigments are derived from mineral compounds, such as metal oxides or salts. Examples include titanium dioxide (white), iron oxides (reds, yellows, browns), and cadmium pigments (yellows, oranges, reds). Organic pigments are carbon-based compounds, often derived from natural or synthetic sources. They tend to be more vibrant than inorganic pigments but can be less stable. Examples include phthalocyanine pigments (blues, greens) and azo pigments (yellows, oranges, reds).

The color of a pigment is determined by its molecular structure and how it interacts with light. Specific wavelengths of light are absorbed, while others are reflected, and it is the reflected wavelengths that our eyes perceive as color. The size and shape of the pigment particles also influence the color and its properties, such as opacity and tinting strength.

Pigments are used in a vast array of applications, including paints, inks, plastics, cosmetics, textiles, and ceramics. The choice of pigment depends on factors such as the desired color, durability, lightfastness, chemical resistance, and cost. Historically, pigments were derived from natural sources like plants, minerals, and insects, but modern pigments are largely synthesized to achieve a wider range of colors and improved performance characteristics.