Introduction to Artists' Pigments
A Description of Artists' Colored Pigments and their Uses
There are more than 1,000 colored pigments usable for artists' paints, but they can be described, categorized and understood using seven simple pairs of words.
The color of almost all artists' paints comes from pigments, which are simply colored powders. Understanding seven pigment categories – transparent or opaque, permanent or impermanent, light or dark, brilliant or grayed, warm or cool, metallic or organic and modern or historical – helps artists choose and use pigments wisely.
For example, genuine rose madder is a cool, medium-dark, fairly brilliant, organic, historical red that is transparent and of limited but usable permanence. An artist illuminating the pages of a book in an antique style would do well using this color, but an artist painting an outdoor mural should avoid it because of its low permanence.
Light or Dark Pigments
The lightness or darkness of a pigment or any color is called the value of the color. White and cadmium lemon are light colors. Black and prussian blue are dark colors. Most pigments' values fall between the lightest and the darkest. For example, cerulean is a medium-dark blue.
For any pigment, the value can vary widely depending on the medium it is used in. Pure phthalo green yellow shade is nearly black in oil paint straight from the tube, but is rather pale in unfixed soft pastel.
Warm or Cool Pigments
This color characteristic is called hue. Warm colors tend toward the redder end of the spectrum. They go from red-violets through reds and oranges, ending with warm yellows.
The cool colors tend toward the blue side of the spectrum. They go from cool, greenish yellows through greens and blues and end with blue-violets.
Brilliant or Grayed Pigments
Fire engine red is a brilliant red. Brick red is a grayed color. Technically, this characteristic of a colored pigment is called chroma or, more simply, intensity.
The medium the pigment is ground in affects this quality of intensity. Thalo green blue shade is extremely brilliant in acrylics, but is rather dull in unfixed pastels.
Metallic and Organic Pigments
Older metallic colors were the earth colors, the lead- and mercury-based colors, and natural semi-precious blues and greens and the "smalt" cobalt blues. The modern cobalt colors and the cadmiums are examples of modern metallic colors.
The older organic colors were made largely from plant saps and insect bodies and sometimes animal products. The newer organic pigments are synthetic compounds. Their hues are often similar to older organics, but the newer organic pigments are much more permanent. Pyrrole red is a good example.
Opaque or Transparent Pigments
Simply put, you cannot see through a layer of opaque pigments while you can see through a layer of transparent pigments. Most pigments fall somewhere between the completely opaque and the completely transparent.
Pigments also have different transparencies in different mediums. For example, a pigment fully transparent in oils may be nearly opaque in soft pastels.
Permanent or Impermanent (also called Fugitive) Pigments
Except for earth colors, most blacks, most cobalt colors and the chromium greens, pigments fade when exposed to light. However, some fade less than others.
The organic pigments are generally less permanent than the equivalent metallic pigments. However, some of the newer organic pigments such as the pyrroles approach the cadmiums in lightfastness and opacity yet are significantly more intense in color.
Historical and Modern Pigments
Historical pigments generally include pigments available before roughly the year 1800. They include the earth colors, carbon-based blacks, and colors made from semi-precious stones and natural organic sources.
The modern colors date from the 1800s. Some are synthetic versions of natural colors. Others are new synthetic colors developed by paint chemists.
Sources:
- The Artist's Handbook of Materials and Techniques, by Ralph Mayer, Viking Press, 1982.
- The Materials & Techniques of Painting, by Kurt Wehlte, Van Nostrand Reinhold, 1982.
- The Oil Color Book by Winsor & Newton, Colart Fine Art and Graphics Limited, 2001.
