Wednesday, December 1, 2021

Unraveling Color Pigment Terms

Organic / Inorganic

Pigments are divided into organic (containing carbon) and inorganic (without carbon). 

Inorganic pigments were traditionally made from natural earths such as the ochres and siennas, and the hard minerals such as azurite and lapis lazuli, plus metals such as cadmium, cobalt, iron, and zinc. They are more opaque, denser, and generally weaker in tints than organic pigments. 

Organic pigments were originally made from plant materials, such as root madder, or animal materials such as cochineal. Organics tend to be more transparent, lighter in weight, and higher in tinting strength. 

Synthetic pigments

Both organic and inorganic pigments can be manufactured artificially in the lab, and the resulting pigments are for the most part indistinguishable from their natural counterparts. 

So, for example, ultramarine is a synthetic replacement for the rare and expensive mineral lapis lazuli. The properties are identical, but the price has become so low that it's used in low cost children's paint. 

Light / Deep

When a color is called "light" or "deep," it doesn't only mean light or dark in value. It also has to do with the position on the hue circle. Cadmium yellow deep is more toward red, really orange, while cadmium yellow light is not only lighter in value but also more toward the green side of yellow. 

Convenience Colors / Hue

Some pigments are blended to make colors with familiar names such as “mauve” or "peacock blue." Convenience mixtures fill gaps by offering intermediate mixtures for which no pigment exists, such as phthalo yellow-green. In watercolor, Payne’s gray is a blue-black made from black and ultramarine or other blends. 

When a color is called a "hue," such as "cerulean blue hue," it's a color that resembles its expensive counterpart, but it's made of a blend of inexpensive ingredients.

Designers Colors

The term "designers color" has been used for a paint color that is meant to match a particular color note. A designers color is made to match not only a hue, but a particular tint or shade and a level of chroma or saturation. Designers colors are often mixed with white to result in colors like "pale rose blush" and "cobalt turquoise light." House paints and hobby acrylics frequently are formulated in this way because people use them right out of the bottle for a given use.

Nowadays most manufacturers of artists' pigments use pure pigments and let you do the adjusting, because you may not want the white in the mixture from the beginning. So if a pigment is naturally transparent, it will still be transparent, even in gouache. 

Permanent / Lightfast

The word “permanent” appears on many different art products, but it’s a confusing term. On some graphic art products, such as inks or felt-tipped markers, it really means “waterproof,” rather than “lightfast” (resistant to fading). Many calligraphy or fountain pen inks are not waterproof, but they’re reasonably lightfast, considering that most handwriting isn’t usually subjected to light for long periods.

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Learn more:

Color terms explained on the website Handprint

Color of art pigment database listed by pigment numbers on website ArtisCreation

Signed copies of my book Color and Light: A Guide for the Realist Painter

Did I get something wrong, or do you have something to add? Please let me know in the comments.



7 comments:

Brenon said...

First time writer, long time admirer. I’m the manager of an art supply store. I tell people about your YT videos whenever someone is looking into watercolor and gouache. In your opinion, what would you suggest as a simple gouache starter set I can build for them to get started. I want people to try it and not get frustrated by it right away. Thank you!

arturoquimico said...

Maestro... I'm a retired chemist and hobby artist / musician... As usual, another great post! Thanks for putting something "left" brained and pragmatic here. I used to give chemistry quizzes to my students and I would often ask how they could distinguish between an organic or an inorganic pure pigment if they were a quality control officer at a paint factory. A model answer was that inorganics tend to be water soluble, but organics tend to be more solvent soluble.

Robert Michael Walsh said...

A couple of minor typo and clarification comments.

James, did you intend "organic" here: "They are more opaque, denser, and generally weaker in tints than inorganic pigments" for organic rather than "inorganic"?

arturoquimico : I think you meant "dye" rather than pigment for solubility. Pigments are usually defined as insoluble particulates, although lake pigments, which have soluble dyes adsorbed on an inert substrate, can be abstracted with an appropriate solvent.

Steve Hall said...

Thanks so much for these concise explanations.

I've always found your seven part Color Wheel series and concluding YURMBY model the easiest tools for explaining color to clients. Bruce MacEvoy's color wheel and value wheel diagrams are helpful, but they require more time reading on the rest of his pages than most people are willing to understand.

James Gurney said...

Robert, thanks: fixed.

Unknown said...

hey james.. how you doing ? i am a big fan from iran..
i love your artwork an style..please keep up the good work thanks.
also,why the photos aren't working?

arturoquimico said...

Yes, "dye" is the more appropriate term... now I know why it was time to retire...