The phthalocyanines, introduced in the early 20th century, were the first class of organic colourants to be introduced directly to the market as ‘true’ pigments, without initially being developed as dyes or lakes.
They were a new class of super pigments with incredibly high performance in terms of tinting strength, lightfastness and chemical resistance and they quickly came to dominate the blue and green pigment markets in all applications.
The phthalo (pronounced ‘thalo’) pigments are immensely important for artists’ due to their intensity and chromatic purity.
After William Perkins’ synthesis of mauve in 1856, the understanding of chemical formulation in the construction of colours expanded very rapidly.
The very first azo pigment was tartrazine yellow, patented in 1884 and still in use as an artist’s pigment today. Chemists were now able to build molecules with greater understanding, and vast numbers of new azo pigments were rapidly introduced. A whole range of b-napthol azo dyes and pigments was introduced after further discoveries in 1895.
A famous family of azo pigments was discovered in 1909, known as the Hansa pigments, although they are chemically known as the Arylide group. A very bright yellow pigment, it was the first of many hues that have been produced from lemons through to warm oranges with great commercial success.
The quinacridones are very intense coloured modern pigments, ranging from yellow-reds through to violet hues. They have excellent lightfastness and have been extensively used in artists’ paints for the last 50 years. Evidence of the quinacridone structure was first uncovered in 1896 but the pigment was not synthesized until 1935. However it took 20 years for any commercial progress to be made.
In 1955 DuPont began investigating the quinacridone pigments. It took until 1958 to perfect the synthesis and introduce this new class of pigments into the market place. Quinacridones are considered ‘high performance’ pigments because they have exceptional colour and weather fastness. Major uses for quinacridones include automobile coatings and industrial coatings. For artists, the pigments offer exceptionally clean transparent colours perfect for glazing and secondary colour-mixing without loss of chromatic value.
Colloquially known as ‘Ferrari Red’, Pyrrole Red was first seen on all red Ferraris from the year 2000. The pigment is based on an organic compound called Diketo-pyrrolo-pyrrole (or DPP for short), first known to have been synthesized in 1974 by a chemistry professor at Michigan State University. Developed by Ciba-Geigy, one of the original modern synthetic pigment manufacturers, it revolutionized the automobile paint industry when it patented the first known method of producing the pigment in 1983. Red paint used by auto manufacturers tended to fade and develop a dusty look known as “chalking.” The pyrroles were, in comparison, extraordinarily bright, stable and resistant to ultraviolet light and extremes of heat and cold. Developed only a few years later, Pyrrole Orange is its yellow-shade cousin. Both share important qualities for artistic use: they are highly opaque (unlike most modern synthetic pigments) highly lightfast, chromatically very pure and non-toxic.