Inorganic vs. Organic Pigments

Titanium dioxide is one of the most widely used inorganic pigments. This opaque white pigment was developed in the 20th century and is extremely popular for its excellent color quality, high hiding power, nontoxic nature, and reasonable cost. It is most commonly used today as a way to provide opacity and lighten other colors. You'll most often see titanium dioxide labeled as titanium white.

White extender pigments are commonly used in industry to improve certain properties while keeping costs low. Some examples of these pigments include calcium carbonate, calcium sulfate, and china clays. Diatomaceous silica is another common type of white extender made from the remains of marine life.

Black pigments are primarily created from carbon particles. For example, carbon black is the most common pigment used in black printing inks.

Also known as natural iron oxide pigments, iron-oxide earth pigments comprise both oxides and oxide hydroxides of iron. This group of pigments creates the earthy ochres, siennas, and umbers found most commonly in paints. Hematite is the most common iron oxide used for red-tone colors like sienna, while hydroxide goethite is found in yellow-tone ochres. Iron and manganese oxides are used to produce brown-tone umbers.

French chemist Nicolas-Louis Vaquelin discovered chromium in 1797 and named it because so many colored compounds could be created from it. In 1809, chromium oxide was used as an enamel in porcelain factories, and it was used as a pigment in paintings as early as 1812. In the modern market, chromium compoundsare used to produce vibrant yellows, oranges, and greens.

Several compounds of cadmium are used in industry today to produce a range of yellows, oranges, reds, and maroons. These compounds are most commonly used to color plastics, but they're also used in ceramics, glass, and paint.

Aluminum and bronze are often used in industry to create metallic inks.

This iron-based pigment is also called Prussian blue, a name originating in the 18th century from the fact that the compound was used to dye the uniforms for the Prussian army. Consisting of iron cations, cyanide anions, and water, iron blue creates its dark blue color through oxidization.

Produced using the root of the madder plant, which also produces Alizarin dye, Alizarin crimson is a synthetic pigment that gained traction in the early 19th century. Also known as Madder red, this pigment can be used to produce various shades of red and red-purple.

Azo pigments are characterized by the fact that they contain a nitrogen group, but are historically significant as being one of the first synthetic organic pigments. Significantly more colorfast than many other types of organic pigments, Azo pigments produce many organic red, orange, and yellow pigments on the market today.

Copper phthalocyanines have been ruling the pigment industry since they were introduced in 1935. Characterized by a brilliant shade, high strength, low cost, and surprising colorfastness despite being organic, this pigment is commonly used to produce strong blues and greens.

Discovered in the 1950s, quinacridone is a common pigment used in industrial and painting applications to produce reds and violets. Unlike many organic pigments, quinacridone exhibits excellent stability in light, heat, alkali, and solvents.

Organic pigments are generally brighter and better in tonal quality compared to inorganic pigments. However, this color tends not to last. For long-lasting products, producers prefer inorganic pigments because they tend to hold their color better in the presence of light and heat than organic pigments.

While organic pigments are very stable on their own, they dissolve in the presence of organic solvents and heat more easily than inorganic pigments. As a result, inorganic pigments tend to be more reliable in various applications.

The variety of colors available varies between organic and inorganic pigments —inorganic pigments come in a wider range than do organic pigments.

Inorganic pigment colors are more economical than organic colorants. Much of this cost difference has to do with manufacturing differences. While organic pigments must go through extensive chemical processing to produce a final product, the processes required for inorganic pigments are comparatively minimal.

Inorganic pigments are easier to disperse than organic pigments. As a result, inorganic pigments are easier to use in large-scale production and can be used for a wider variety of applications.

Pigments work by selectively absorbing wavelengths of light, but the process by which this occurs differs between organic and inorganic pigments. In organic pigments, the conjugated systems of double bonds within the molecules absorb the light. In inorganic pigments, on the other hand, the light is absorbed through electron transfer.

Organic pigments and inorganic pigments differ in particle size —inorganic pigments have significantly larger average particle sizes than organic pigments. Larger particles scatter light more effectively, preventing it from passing through the substance and resulting in better opacity. This is why organic pigments are considered transparent while inorganic pigments are opaque.

While organic pigments tend to be smaller in size than inorganic pigments, their surface area is generally larger. As a result, organic pigments tend to create stronger, brighter colors.

Determine if the opacity of the color is important to your project. Organic pigments are transparent, while inorganic pigments are opaque. This means that a single layer of organic pigment may not be sufficient to create a good color layer, but a single layer of inorganic pigment may provide sufficient coverage to conceal the

If color vibrancy is important to your project, remember that organic pigments tend to create brighter colors than inorganic pigments. In certain cases, organic pigments or dyes can be used with inorganic pigments to create more vibrant colors.

If your project is going to be exposed to light and weather, and you need it to retain its color quality, then inorganic pigments may be more appropriate. While organic pigments are brighter, inorganic pigments are more resilient to sunlight, weather, and chemical exposure. There are some exceptions to this rule, so be sure to consider lightfast organic pigments if vibrancy is just as important as resilience.