Categories
Education Notes from the Lab

Modern and Post-Modern Pigments: Cadmiums vs. Bismuth Yellow and Pyrrole Red

Painters today are offered a considerable breadth of choices when selecting paints. It’s easy to become overwhelmed. We might default to using the pigments our instructors taught us to use or those we have simply used for many years. The wide accessibility and relative affordability of so many pigments is nothing short of modern miracle, sustained on by a global system of trade and manufacture. Rather than fear the long shelves of unfamiliar pigments I hope I can convince you that these options are often solutions to our artistic aims.

Those new to painting may search ‘essential paint colours’ and find most lists include some variation of cadmium yellow and red. These are the iconic, bright, opaque colours that have been loaded onto painters’ palettes for nearly two centuries now. Today’s article makes the case for cadmium’s post-modern ancestors, bismuth yellow and pyrrole red. Where did these pigments come from and why should you choose them instead of cadmium colours?

drawdown swatch of yellow and red

Figure 1: Cadmium Yellow (Medium, PY 35), Bismuth Yellow (Medium, PY 184), Cadmium Red (Medium PR 108), Pyrrole Red (opaque, PR 254)

Heavy Hitters: A history of Cadmium Pigments

Although they may seem firmly historical, heavy metal cadmium pigments (red, yellow and orange) actually have somewhat recent history, but certainly one that has made a prolific splash. The critical elements of these iconic colours, cadmium and selenium, were not discovered until 1817.[1] When the German metallurgist Friedrich Stromeyer discovered cadmium in 1817, he immediately recommended his brightly coloured cadmium sulphide compound for use as an artist’s pigment. It would take the work of another chemist, the Swedish Jöns Jacob Berzelius, with his discovery of selenium, to make orange and red shades of cadmium with the addition cadmium selenide to Stromeyer’s cadmium yellow.[2] Cadmium pigments now also contain a portion of zinc sulphide which in combination with yellow cadmium sulphide which yields cool, light hues of colour like cadmium yellow primrose.[3]

a row of cadmium paint swatches from yellow to red

Figure 2: Tri-Art High Viscosity Clinically Pure Cadmium Colours: Yellow Light (PY 35, with the most zinc sulphide), Yellow Medium (PY 35), Orange (PO 20, with increasing cadmium selenide), Red Medium (PR 108, with the most cadmium selenide).

Cadmium pigments appears as early as 1829 in oil paintings in France and Germany but were slow to take off. Cadmium pigments were not commercially available until 1840[4] with a very limited supply of raw materials – to this day there are no readily accessible sources of cadmium and selenium, and so these components must be processed out of other mining waste. [5] Scarcity persisted throughout the 19th century with one first-hand account from 1888 noting cadmium yellow as “a perfect colour if not so expensive.” [6]

Despite their cost, these pigments gained popularity for their enduring colour, especially in the heavily polluted air of 19th century coal-burning cities.[7] They found use in oils and watercolours, where small amounts of the costly pigments could be appreciated. The famous colours of the Impressionists certainly owe a great dept to the bright, opaque shades of cadmium colours that added chroma to their a la prima palettes. Monet’s works have been extensively documented to contain cadmium yellow, as seen in the warm yellow hues of Bordighera (1884).[8]

a painting, bordighera by claude monet

Figure 3: Claude Monet, Bordighera, 1884, The Art Institute of Chicago, Illinois. Public Domain, circa wiki Images.

The 1920s brought the industrialization of cadmium pigments. It was discovered that cadmium colours could be extended with inexpensive lithopone filler while still remaining colourful and opaque. With this, cadmiums became one of these most important commercial pigments, still being produced in mass quantities to this day. [9] Quality artists’ paints continued to use unadulterated cadmium colours to capitalize on the vibrancy of these pigments, but at a premium cost. The ubiquitous nature of these colours on nearly any painter’s palette is a testament to their beloved working qualities, and perhaps lack of alternatives.

Bismuth as Usual? The Long History of A Post-modern Yellow

You may be familiar with bismuth metal in its crystallized state, an impossibly geometric and prismatic structure, commonly sold in shops. While these are modern synthetic crystals, bismuth as a white metal was known to the ancients and found use in artworks as early as the 15th century. The metallic quality of bismuth meant it could be utilized as an economical substitute for silver, most commonly found as a powdered pigment for illuminating of manuscripts or oil paintings.[10] The pigment was likely more grey than metallic, with a slight lustre similar to metal-point drawings or modern graphite. Painters like Francesco Granacci (1469–1543) may have tried to utilize this lustrous quality when painting metallic surfaces like the armour in Portrait of a Man in Armour (ca. 1510). Modern analysis found the grey to be bismuth based.[11]

synthetic bismuth crystal

a painting, a portrait of a man in armor

Figure 4: Modern Synthetic Bismuth Crystal by Dschwen. CC 2.5. Via Wiki Images.

Bismuth Metal Ingots. By Unconventional2 – Own work, CC BY-SA 4.0, via Wiki Images.

Francesco Granacci (1469–1543), Portrait of a Man in Armour (ca. 1510). National Gallery of Art, Washington DC. Public Domain, via Wiki Images.

Metallic bismuth as a pigment does not appear to have gained wide traction in history, and only in the 20th century was the metal explored for its colorful possibilities. Beginning in the 1960s the spectral effect of bismuth crystals was capitalized on in the form of a nail polish additive – bismuth oxychloride was utilized as a replacement for naturally pearlescent materials.[12] Contemporary bismuth yellow pigments were only introduced to market in 1985 after many decades of experimentation.[13]

3 bismuth yellow colour swatches

Figure 5: Post-modern yellows. Tri-Art Liquids Bismuth Yellow (PY 184) in Light, Medium and Deep Hues.

Bismuth Yellow (labeled PY184 on artists paints) is a mixture of two metal oxides, bismuth vanadate and bismuth molybdate. Bismuth vanadate was first synthetized in 1924 for pharmaceutical purposes. In 1976 DuPont began developing this compound as a pigment. They described their bismuth vanadate as ‘brilliant primrose yellow.’ Mixed metal oxide version of vanadate and molybdenum were later synthesized, giving rise to warmer orange-red shades.[14] Tri-Art offers shades from light to deep, similar to shades of cadmium yellow. Approximately 900 tonnes of bismuth yellow are now produced annually, [15] largely for industrial, outdoor applications due to its outstanding lightfastness.

Pyrrole Reds: A Fiery Future

Pyrrole red is a relatively new pigment – it was first synthesized in 1974 by accident. [16] Despite its infancy, many of us will have encountered this pigment in everyday life, the pigment has become widely used in automobile paints, plastics and cosmetic formulations (labeled CI 56110).[17], [18]

two pyrrole red swatches

Figure 6: Tri-Art Liquid Acrylic Pyrrole Red Light (PR 255) and Medium (PR 254).

When pyrrole red was first synthesised, the accidental biproducts had enticing properties as pigments: highly insoluble, highly stable, and intensely red in colour. The product had an incredibly high chroma red colour due to their synthetic, high purity.[19] The pigment was first introduced as Irgazin DPP in the 1980s by Ciba-Geigy.[20] It now comes in a range of hues from orange to bluish-red.[21] Tri-Art offers pyrrole red light and medium in similar shades to cadmium reds.

Modern vs. Post-Modern pigments: Which are better?

Cadmium pigments are considered staple of the serious painter’s palette – intensely opaque, they offer great colour coverage and tinting strength, especially when mixing with titanium white. However, cadmium colours have always been cost prohibitive and will continue to be so due to the scarcity of available cadmium and selenium on earth. Cadmium pigments also have record of causing problems for painters and conservators. In their 19th century infancy cadmium pigments were particularly unreliable; contaminants left over from the processing of cadmium pigments from raw ore could cause disastrous deteriorations to painted surfaces in just a few decades. Many 19th century paintings with once bright, richly saturated yellows now appear bleached white, cloudy, or chalky in appearance. Several cases show the opposite effect too, with mixtures of cadmium yellow and other pigments like chrome yellow and the famous Emerald Green (composed of deathly toxic arsenic) inciting reactions that markedly darken the paint film. It really took the improvements of 20th century chemistry to bring us chemically pure cadmium pigments that were consistently stable in the 1940s.[22]

Despite finding stability in chemically pure formulations, cadmium pigments remain problematic because of their heavy metal nature. Toxicological and environmental impacts are something that every painter should consider when deciding if they want to use these pigments. Because of these issues, pyrrole red and bismuth yellow are often suggested as replacements for these pigments. Pyrrole red is nearly just as opaque as cadmium red, intensely red, outstandingly light-fast, and non-toxic. [23] Because of its safety profile, the pigment is safe enough to be used in tattooing, cosmetics and all paint formulations. Unlike cadmium colours, post-modern pigments like pyrrole red and bismuth yellow can found in liquid and spray paints – cadmium colours, in contrast, should not be sprayed to avoid any inhalation.

cadmium red swatches next to pyrrole red swatches

Figure 7: Tri-Art High Viscosity Acrylics. Cadmium Red (Medium Shade, PR 108) and Pyrrole Red (medium shade, PR 254). Straight from the tube, as a tint with titanium white (PW 6), and as a wash with water.

Bismuth yellow is similarly non-toxic, with a very high opacity, and an intense yellow colour. Although a metal oxide, it appears that bismuth yellow is an environmentally conscious choice with impact studies noting virtually no risk to human or aquatic life.[24] Bismuth yellow also has excellent lightfastness, being used extensively for outdoor applications.[25] Like cadmium pigments, bismuth yellow is an expensive pigment, owing to the cost of raw materials. Like cadmium, bismuth is somewhat scarce and therefore can only be sourced as a biproduct of mining other metals.[26]

cadmium yellow swatches next to bismuth yellow swatches

Figure 5: Post-modern yellows. Tri-Art Liquids Bismuth Yellow (PY 184) in Light, Medium and Deep Hues.

Pyrrole red has the additional advantage of coming in a range of not only shades, but also transparency. Unlike cadmium colours, the particle size of pyrrole red can be manipulated to make transparent and opaque formulations. Painters may be more familiar with this colour than they think – transparent pyrrole red has been used to create the red filter of RGB type LCD screens.[27] Although these screens project colour rather than reflecting it as in a painting, modern artists may find they can reproduce the high chroma colours we see every day through our screens more faithfully using contemporary pyrrole pigments versus muddier cadmium colours. Transparent pyrrole reds are additionally more lightfast than many other transparent reds that are used to formulate colours like alizarin crimson.

red drawdown colour swatch

Figure 9: Tri-Art Liquid Acrylics, Transparent and Opaque Pyrrole Red, Medium Shade (both PR 254).

a macro example rgb pixels displaying different colours

Figure 10: LCD screen showing individual pixels of red, green and blue. The red filter can be made using transparent pyrrole red. By Luís Flávio Loureiro dos Santos, via Wiki Images. CC 3.0.

Testing out Bismuth Yellow, Pyrrole Red and Cadmium Colours

Advantages of Pyrrole Reds:

  • Pyrrole red is non-toxic, and more ecologically friendly than cadmium colours.
  • Despite its price point, the very high tinting strength of Pyrrole red allows this colour to go very far – Tri-Art’s high quality, highly pigmented, professional formulations further ensure you get the most pigment and colour possible.
  • Pyrrole colours are the closest alternative to cadmium colours rather than cadmium hues currently on the market.[28] Hue colours must balance an accessible cost with replicating the hue of another pure pigment. If you are looking to replace heavy metal pigments like cadmiums from your palette at a professional level – pyrrole is the best choice.
  • Pyrrole red creates cleaner secondary colours, less warm and muddy than cadmiums. Its high chroma also competes better with other high chroma colours like phthalo blue and high tinting colours like titanium white.
  • Pyrrole red has options for opaque and transparent variations – if you can become familiar with its colour properties you can readily extend your working palette to transparent reds rather than reaching for other hues of red.

cobalt and magenta paint swatches

Figure 11: Cobalt Blue and Manganese Blue Hue (phthalo blue) mixed with cadmium red (left row), pyrrole red (right row), and the resulting mixtures with titanium white (bottom row). Pyrrole red created a richer purple with both blues, while cadmium produced warmer, muted hues. When up against titanium white, pyrrole red colours remained more saturated in chroma, with cadmium colours becoming even more muted.

bismuth, cadmium, and pyrrole swatches on two cards

Figure 12: Bismuth Yellow (left) and Cadmium Yellow (right) mixed with cadmium red (left row), pyrrole red (right row), and the resulting mixtures with titanium white (bottom row). Results were similar to mixing purple secondaries, with pyrrole red producing richer, more saturated colours, even when mixed with titanium white.

Advantages of Bismuth Yellows:

  • Bismuth yellow is ecologically more friendly than cadmium colours and non-toxic.
  • Like pyrrole red, bismuth yellow creates cleaner secondary colours. I found bismuth yellow most convincing when mixing green hues – it readily produced more neutral greens than cadmium yellow that always appeared yellow and warm shaded.
  • Last year Tri-Art introduced a newly modified bismuth pigment which improved grinding and dispersing for their bismuth yellow acrylic paint. The new pigment creates a paint with higher gloss, greater chroma and saturation, and requires a less energy intensive process to create.

cobalt and manganese swatches

Figure 13: Cobalt Blue (left) and Manganese Blue Hue (phthalo blue)(right) mixed with cadmium yellow medium (left row), bismuth yellow medium (right row), and the resulting mixtures with titanium white (bottom row). Bismuth yellow created a more neutral green when mixed with both blues, while cadmium produced warmer, yellow hues.

By now all but the traditionalist painter might be convinced of these contemporary pigments. But for those who would like to replicate the works of 19th and 20th century geniuses I would offer one last thought. While making my colour charts, I also found that bismuth yellow was able to make a beautiful shade of bright and cool green with phthalo blue and titanium white – the colour reminded me of the infamous Emerald Green. Thankfully no longer available due to its incredibly toxic arsenic content, the bright and densely opaque green colour dominated the art world of the 19th century. Degas possibly used the pigment when painting his ­Dancer with Bouquets (1895-1900), adding bright flourishes of cool green. Whatever your artistic aims, I would suggest that pigments like pyrrole red and bismuth yellow offer painters, both modern and classical alike, the ability to mix a wider range of colours while retaining vibrancy and saturation when creating tints with titanium white. Consider trying them for your next project.

a painting, dances with bouquets by edgar degas

Below, Bismuth Yellow, phthalo blue and titanium white mixtures

Figure 14: Edgar Degas, Dancer with Bouquets, 1895-1900, oil on canvas. Chrysler Museum of Art. Public domain. Below, Bismuth Yellow, phthalo blue and titanium white mixtures. The bright touches of green in this work are possibly the infamous arsenic based emerald green, a colour that can no longer be obtained. Replicating the colour with modern pigments like bismuth yellow worked better than cadmium colours.

When to reach for Cadmium Reds and Yellows:

Despite their drawbacks, cadmium colours will continue to hold an important place in the painters’ palette. For the contemporary painters looking to evaluate their painting practice you may want to consider using cadmium colours for the follow purposes:

  • Trying to replicate a historical palette (note that many historical colours are not available due to their toxicity or fugitive nature)
  • Opacity is critical (pyrrole red and bismuth yellow are slightly less opaque than cadmium colours)
  • You are looking to achieve a palette that is warm or low in chroma while keeping colour mixtures minimal
  • For those on a budget, cadmium hue colours can be explored too. However, these will be most useful for those who paint straight from the tube, without extensive colour mixing.

Bibliography

Abel, A, ‘Pigments of the Industrial Revolution’, in Colour Design – Theories and Applications, ed. by Best Janet, 2nd Editio (Cambridge: Elsevier, 2017), pp. 572–74

Berrie, Barbara H, ‘Rethinking the History of Artists’ Pigments Through Chemical Analysis’, Annual Review of Analytical Chemistry, 5.1 (2012), 441–59 <https://doi.org/10.1146/annurev-anchem-062011-143039>

Buxbaum, Gunter, ed., ‘Bismuth Pigments’, in Industrial Inorganic Pigments, Wiley Online Books (Weinheim: Wiley, 1998), pp. 113–16 <https://doi.org/https://doi.org/10.1002/9783527612116.ch3>

Čechák, Tomáš, Tomáš Trojek, Radka Šefců, Štěpánka Chlumská, Anna Třeštíková, Marek Kotrlý, and others, ‘The Use of Powdered Bismuth in Late Gothic Painting and Sculpture Polychromy’, Journal of Cultural Heritage, 16.5 (2015), 747–52 <https://doi.org/10.1016/j.culher.2014.12.004>

Dunning, Paul, ‘Cadmium Pigments’, High Performance Pigments, Wiley Online Books, 2009, pp. 13–26 <https://doi.org/https://doi.org/10.1002/9783527626915.ch3>

Endriss, Hartmut, ‘Bismuth Vanadates’, in High Performance Pigments, Wiley Online Books, 2009, pp. 7–12 <https://doi.org/https://doi.org/10.1002/9783527626915.ch2>

Fiedler, Inge, and Michael Bayard, ‘Cadmium Yellows, Oranges and Reds’, in Artists’ Pigments: A Handbook of Their History and Characteristics, ed. by Robert L Feller (Washington DC: National Gallery of Art, Washington DC, United States, 1986), p. pp.65-108

Greening, Timothy, ‘Metamerism in Colour Mixtures Containing Cadmium Red and Pigment Red 254’ (Queens University, 2013)

Krüger, Joachim, Peter Winkler, Eberhard Lüderitz, Manfred Lück, and Hans Uwe Wolf, ‘Bismuth, Bismuth Alloys, and Bismuth Compounds’, Ullmann’s Encyclopedia of Industrial Chemistry, Major Reference Works, 2003 <https://doi.org/https://doi.org/10.1002/14356007.a04_171>

Lewis, Peter A., ‘Colorants: Organic and Inorganic Pigments’, in Color for Science, Art and Technology, ed. by Kurt. Nassau, Azimuth ; v. 1. (Amsterdam ; Elsevier, 1998), pp. 283–312

Lomax, Suzanne Quillen, and Tom Learner, ‘A Review of the Classes, Structures, and Methods of Analysis of Synthetic Organic Pigments’, Journal of the American Institute for Conservation, 45.2 (2006), 107–25 <http://www.tandfonline.com/doi/abs/10.1179/019713606806112540>

Wallquist, Olof, and Roman Lenz, ‘Diketopyrrolopyrrole (DPP) Pigments’, High Performance Pigments, Wiley Online Books, 2009, pp. 165–94 <https://doi.org/https://doi.org/10.1002/9783527626915.ch11>


Categories
Education

Sun Kissed & Science Based: Tri-Art Oil Formulations

Sandro Botticelli, Venus and Mars, c 1485. Tempera and oil on poplar panel, 69 cm x 173 cm, National Gallery, London. Public Domain. Circa Wiki Images.

Beneath their colourful appearance and creamy textures, oil paints conceal a fascinating formulation that has evolved considerably since their rise to popularity in 15th century Renaissance Europe. Oil and pigment are only the beginnings of crafting artists’ quality oil paints, especially in modern formulations. Today a range of natural oils, drying agents, and semi-synthetic alkyds are used to manufacture high quality artists’ oil paints.

©Austin Howlett, Untitled, 2020, oil on panel, 18″x24.” Painted with Tri-Art oil paints.

Plants, Paint and Polymerization: Understanding Historical Oil Choices

Not all oils are made equal. Most of the oils in our cupboards are unsuited to making paint. If applied to any surface, they would remain hopelessly sticky, if not merely liquid, forever. Oils for paint must be carefully selected for their ability to ‘dry.’ Unlike water-based mediums like acrylics, oils do not ‘dry’ through an evaporative process but undergo a chemical reaction that changes the liquid oil into a solid film. This is partly why oil paints can be more highly pigmented than water-based acrylic paints – they exhibit no volume loss on drying, leaving the maximum amount of binder to hold the colour particles.

Within a bottle of oil is a mixture of fats called lipids. The properties of these lipids, and the oil, are defined largely by the content of even smaller component parts, the fatty acids. You may recognize some broad categories found on nutritional labels like saturated, unsaturated and trans-fats. In drying oils used to make paint, the majority of fatty acids will be unsaturated, meaning they contain chemically reactive sites that will allow the oil to undergo a complex series of reactions called polymerization. In the presence of oxygen, the reactive sites slowly link together, transforming the free-flowing lipid molecules into a solid film formed by a large tangled network.

Historically and to this day, linseed oil continues to be one of the most popular drying oils. It’s extracted from the flax plant, also the source of linen, long used as a canvas for painting. Jan Van Eyck is often falsely miscredited for inventing oil painting in the 15th for his mastery of his technique – finely glazing and blending layers of linseed oil paint.[i] Linseed oil became the most popular drying oil for paint because it contains a high portion of the fatty acid linolenic acid. With several reactive sites, linolenic acid gives linseed oil the fastest drying rate of any unmodified, natural oil. The many bonds created between these fatty acids also create a robust, strong oil film. Nearly every painting you see preserved in a museum for us to enjoy owes its thanks to the humble flax plant – linseed oil remained a staple from the wild Renaissance works of Hieronymus Bosch, to the modernists of the 20th century.

Flowers of the flax plant (Linum usitatissimum), Ottawa, Ontario, Canada by D. Gordon E. Robertson. CC BY-SA 3.0.

Jan Van Eyck. The Arnolfini Portrait, oil on oak, 1434. National Gallery, London. Public Domain, via Wiki Images. Jan Van Eyck is often falsely credited with inventing oil painting for his early and sublime mastery of the media.

Despite its vast popularity, the fast and well drying linseed oil came with a catch. Even when highly refined, the oil remains slightly yellow in tone. This imparts a slight warm tone, effecting pale cool colors like white, yellow, and blue. Furthermore, as the oil paint dries and ages it has a tendency to yellow more. Historically other oils like walnut and poppyseed were used in attempt to circumvent this problem. Although much slower drying, these oils are also considerably less yellow to begin with. However, when allowed to fully dry, these traditional oils all likely produce paint that is indistinguishably yellowed to the human eye.[ii] When working with these mediums today it recommended that you select these not for their possibly outdated, perceived optical properties, but for their classical handling characteristics and drying time.

Linseed Oil (with seed and flax plant) By Handwerker – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=18045027

Juglans regia (the Common walnut or Persian walnut) By Böhringer Friedrich – Own work, CC BY-SA 2.5.

Beyond the Pale: Safflower and Sunflower

In search of alternative, non-yellowing oils, ultra-pale oils like safflower and sunflower oil were introduced into artists oil paints during the 1960s.

Carthamus tinctorius (Safflower) via Wiki Images.

Sunflower © Tomas Castelazo, www.tomascastelazo.com / Wikimedia Commons

The reasons for oils yellowing remains highly elusive, but oils with less linolenic acid like poppyseed, safflower and sunflower will tend to stay slightly more colourless as they age,[iii] with studies showing that safflower remains the most true to colour.[iv] Tri-Art has gone the distance to formulate their range of modern oil paints with sunflower oil. Sunflower oil contains almost no linoleic acid and is the palest drying oil currently available (paler than safflower). Not just white, but the majority of the oil line has been formulated with sunflower oil to ensure purity of colour out of the tube and over time.

Because these oils lack linolenic acid, they are also extremely slow to dry, if at all. Sunflower oil also contains antioxidant tocopherols that further inhibit the drying process that allow us to turn the oil into paint.[v] In order to capitalize on these ultra-colorless oils another additive is necessary: a drier.

Solidifying Concepts: Driers

Since its rise to popularity in the 15th century, artists have been augmenting their oil paints with additives like waxes, resins, solvents, and drying agents. Drying agents help speed the process of slow drying oils and help ensure that thickly painted impastos dry through. They work by catalyzing the polymerization reaction of the oil medium.

Historically, lead pigments would promote very effective through drying. Any area of paint that could include a white tint would greatly benefit from a small amount of this pigment that would not only speed the drying, but create an incredibly long-lasting, durable paint film. Other options included zinc, in the form of white vitriol (zinc sulphate) and ground glass, containing calcium and magnesium ions. These options are colourless and could be used to formulate any paint colour. For instance, these driers are both found in rich purples of the man’s robe in Jan van Eyck’s Arnolfini Portrait (1434). The Venetian master painter Titian would later use white vitrol in his Portrait of a Lady (1510-12) to speed the drying of his priming layers and the notoriously slow drying black colours. By the 18th and 19th century white vitriol was a popularly mentioned drier in artists’ painting manuals and catalogues.[vi]

Titian, Portrait of A Lady (“La Schiavona”), 1510-12, oil on canvas, National Gallery, London. Via Wiki Images. Public Domain. Titian used zinc driers, in the form of white vitriol to speed his priming layers and the drying of very slow drying black paints.

Zinc and calcium found in white vitrol and powdered glass remain popular in the formulation of driers today, but by far cobalt is the most popular drying agent. Historically cobalt could be added to paint as smalt – a blue glass coloured by cobalt.[vii] Today cobalt metal soaps are utilized with unparalleled effectiveness. They cause the paint film to dry to the touch quickly – even sometimes too quickly. Zinc is added to slow the action of the cobalt drier and allow the paint to evenly dry through the thickness of the film, preventing wrinkling of the surface. Further additions of calcium can aid with other characteristics like hardness and gloss.[viii] Research has shown only small amounts of cobalt driers are necessary to catalyze the drying of oil paint, and the results appear to be stable over the long term.[ix]

Tri-Art’s takes full advantage of the ultra-colourless characteristics of sunflower seed oil by utilizing these driers to create an oil paint that will dry to a stable and long-lasting paint film. This provides the ideal medium to highlight Tri-Arts finest quality pigments like quinacridone red. These are sourced internationally before being ground locally in Kingston, Ontario to the highest standard of quality. At Tri-Art all oil colours are formulated at a professional artist grade, meaning that the highest pigment load possible has been balanced with excellent handling qualities. This gives each color its maximum saturation and a creamy texture to complement the crystal-clear sunflower oil medium. Artists like Tylor McNeil have capitalized on this brilliant colour in works like XIV (Rose Series). The clarity of Tri-Art’s sunflower oil paint should ensure that McNeil’s pastel palette remains light and bright for decades to come.

©Tylor McNeil, XIV (Rose Series), 2020. Tri-Art Gesso and Oils on wood panel. www.tylormcneil.com
Colours used: Permanent Alizarin crimson, Quinacridone Red, Cadmium yellow medium hue, Phthalo Blue, Titanium White and Carbon Black.

Contemporary Colours & Modern Mediums: The Alkyds

For the modern painter, the choice of pigments is now nearly endless. Tri-Art has formulated a range of contemporary paints for the oil painter looking to expand their palette into the 21st century. Iridescent and interference colors are available in oil paint’s modern predecessor, alkyd. Seen here in the work of Kim Dorland, a specialty pigment, micaceous iron oxide, in alkyd resin creates an alluring subtle shimmer to the grey-black elements.

©Kim Dorland, Vigil, 2020, oil and acrylic on canvas, 72×60 inches. Featuring Tri-Art alkyd-oil in micaceous iron oxide.

By modifying a drying oil like linseed with a polyester resin, heat and glycerol, a new product is formed. Alkyds are oil-like in their handling qualities, but faster drying than oil, often due to the addition of a chemical drier in their formulation. Like traditional drying oils, the alkyd dries via a process of oxidative polymerization.[x]

Alkyds were the 20th century solution to the working difficulties of traditional oil paints – they were and remain to be one of the most important paint mediums of the 20th and 21st century. First synthesized in the 1920s, alkyds’ initial conceptions were difficult to work with and generally unpopular. It was utilized as a second-rate automobile coating mostly and later in the 1940s to coat war machinery. By the end of the decade, then surplus war-time paint and chemical factories needed to develop new paint formulations that were more user friendly if they wanted to survive in a civilian marketplace. During the 1950s easy to apply formulations made with cheap soy and cotton seed oil made alkyd paints incredibly popular as affordable housepaint. Previously house paints were often oil-resin based and applied by hired painter-decorators. With the advent of alkyd house paints, the DYI era of home décor really began.[xi]

Alkyd paints quickly became popular with artists, even though they were not designated for such use.[xii] Picasso is thought to have experimented with alkyd paints as early as 1932.[xiii] Others include Franck Stella and later Jackson Pollock. Early alkyds were available as housepaint and industrial coatings, meaning they were flowing, thin paints.[xiv] This flow was coveted by modernist painters looking to eschew the old ways of oil painting with brushes and palettes, instead painting flat fields of colour that would come to typify the mid-century art movement in North America.

Like acrylics, alkyds have come a long way since their initial conception. Artists quality alkyds would not be introduced until 1970s. Unlike the early alkyd industrial car and house paints, artist formulations like Tri-Art’s finest quality alkyds are formulated to be nearly solvent free and clear upon drying. Fumed silica is the modern update to powdered glass that gives Tri-Art alkyds their creamy, bodied texture.

From Ancient to Modern: Oil to Alkyd

In 1434 Jan Van Eyck painted The Annunciation using the medium he perfected – linseed oil colours. The prismatic plumage of the angel’s wings was to become a popular feature of 15th century Netherlandish devotional painting. The colorful effect he depicted now finds a modern antecedent in the spectral pigments of modern artists oils and alkyds like Tri-Arts finest artist oils and alkyds. Paint formulations have considerably evolved since van Eyck put his brush to a palette, but artists desires to create with the lush, richly saturated colours of oil endures.

Jan Van Eyck. The Annunciation, Oil transferred from wood to canvas, c. 1434. National Gallery of Art, Washington, D.C.. Via Wiki Images. Public Domain.

Tri-Art Oil Colours

Bibliography

Cairns, L K, and P B C Forbes, ‘Insights into the Yellowing of Drying Oils Using Fluorescence Spectroscopy’, Heritage Science, 8.1 (2020), 59 <https://doi.org/10.1186/s40494-020-00403-1>

Cappitelli, Francesca, and Fotini Koussiaki, ‘THM-GCMS and FTIR for the Investigation of Paints in Picasso’s Still Life, Weeping Woman and Nude Woman in a Red Armchair from the Tate Collection, London’, Journal of Analytical and Applied Pyrolysis, 75.2 (2006), 200–204 <https://doi.org/https://doi.org/10.1016/j.jaap.2005.05.008>

Gifford, E Melanie, ‘Van Eyck’s Washington Annunciation: Technical Evidence for Iconographic Development’, The Art Bulletin, 81.1 (1999), 108–16 <https://doi.org/10.1080/00043079.1999.10786874>

van Gorkum, Remy, and Elisabeth Bouwman, ‘The Oxidative Drying of Alkyd Paint Catalysed by Metal Complexes’, Coordination Chemistry Reviews, 249.17 (2005), 1709–28 <https://doi.org/https://doi.org/10.1016/j.ccr.2005.02.002>

Izzo, Francesca Caterina, ‘20th Century Artists’ Oil Paints : A Chemical-Physical Survey’, ed. by Guido Biscontin (Venice: Università Ca’ Foscari Venezia, 2011)

Learner, Thomas J S, ‘Modern Paints: Uncovering the Choices’, in Modern Paints Uncovered: Proceedings from the Modern Paints Uncovered Symposium, ed. by Thomas J S Learner, Patricia Smithen, Jay W Krueger, and Michael R Schilling (Los Angeles: Getty Conservation Institute, Los Angeles, United States, 2007), p. pp.3-16, 10 figs. (6 color), 2 tables, refs.4 no

Llamas Pacheco, Rosario, and Amparo Torrente Casado, ‘Medios y secativos en la pintura al óleo actual: una revisión de su uso y comportamiento’, Conserva, no.17, 17, pp.79-93, 8 photos, 6 tables, 19 notes, bibliog.

Mühlethaler, Bruno, and Jean Thissen, ‘Smalt’, in Artists’ Pigments: A Handbook of Their History and Characteristics. Volume 2 (Washington DC: National Gallery of Art, 1993)

Sands, Sarah, ‘On the Yellowing of Oils’, Just Paint, 2019 <https://www.justpaint.org/on-the-yellowing-of-oils/> [accessed 30 November 2020]

Spring, Marika, ‘New Insights into the Materials of Fifteenth- and Sixteenth-Century Netherlandish Paintings in the National Gallery, London’, Heritage Science, 5.1 (2017) <https://doi.org/10.1186/s40494-017-0152-3>

Standeven, Harriet, ‘“Cover the Earth”: A History of the Manufacture of Household Gloss Paints in Britain and the United States from the 1920s to the 1950s’, in Modern Paints Uncovered: Proceedings from the Modern Paints Uncovered Symposium (Los Angeles: Getty Conservation Institute, 2007)

Wicks Jr., Zeno W, ‘Drying Oils’, KirkOthmer Encyclopedia of Chemical Technology, Major Reference Works, 2002 <https://doi.org/https://doi.org/10.1002/0471238961.0418250923090311.a01.pub2>


[i] E Melanie Gifford, ‘Van Eyck’s Washington Annunciation: Technical Evidence for Iconographic Development’, The Art Bulletin, 81.1 (1999), 108–16 <https://doi.org/10.1080/00043079.1999.10786874>.

[ii] Sarah Sands, ‘On the Yellowing of Oils’, Just Paint, 2019 <https://www.justpaint.org/on-the-yellowing-of-oils/> [accessed 30 November 2020].

[iii] L K Cairns and P B C Forbes, ‘Insights into the Yellowing of Drying Oils Using Fluorescence Spectroscopy’, Heritage Science, 8.1 (2020), 59 <https://doi.org/10.1186/s40494-020-00403-1>.

[iv] Sands.

[v] Francesca Caterina Izzo, ‘20th Century Artists’ Oil Paints : A Chemical-Physical Survey’, ed. by Guido Biscontin (Venice: Università Ca’ Foscari Venezia, 2011).

[vi] Marika Spring, ‘New Insights into the Materials of Fifteenth- and Sixteenth-Century Netherlandish Paintings in the National Gallery, London’, Heritage Science, 5.1 (2017) <https://doi.org/10.1186/s40494-017-0152-3>.

[vii] Bruno Mühlethaler and Jean Thissen, ‘Smalt’, in Artists’ Pigments: A Handbook of Their History and Characteristics. Volume 2 (Washington DC: National Gallery of Art, 1993).

[viii] Zeno W Wicks Jr., ‘Drying Oils’, Kirk‐Othmer Encyclopedia of Chemical Technology, Major Reference Works, 2002 <https://doi.org/https://doi.org/10.1002/0471238961.0418250923090311.a01.pub2>.

[ix] Rosario Llamas Pacheco and Amparo Torrente Casado, ‘Medios y secativos en la pintura al óleo actual: una revisión de su uso y comportamiento’, Conserva, no.17, 17, pp.79-93, 8 photos, 6 tables, 19 notes, bibliog.

[x] Remy van Gorkum and Elisabeth Bouwman, ‘The Oxidative Drying of Alkyd Paint Catalysed by Metal Complexes’, Coordination Chemistry Reviews, 249.17 (2005), 1709–28 <https://doi.org/https://doi.org/10.1016/j.ccr.2005.02.002>.

[xi] Harriet Standeven, ‘“Cover the Earth”: A History of the Manufacture of Household Gloss Paints in Britain and the United States from the 1920s to the 1950s’, in Modern Paints Uncovered: Proceedings from the Modern Paints Uncovered Symposium (Los Angeles: Getty Conservation Institute, 2007).

[xii] Harriet Standeven, ‘“Cover the Earth”: A History of the Manufacture of Household Gloss Paints in Britain and the United States from the 1920s to the 1950s’, in Modern Paints Uncovered: Proceedings from the Modern Paints Uncovered Symposium (Los Angeles: Getty Conservation Institute, 2007).

[xiii] Francesca Cappitelli and Fotini Koussiaki, ‘THM-GCMS and FTIR for the Investigation of Paints in Picasso’s Still Life, Weeping Woman and Nude Woman in a Red Armchair from the Tate Collection, London’, Journal of Analytical and Applied Pyrolysis, 75.2 (2006), 200–204 <https://doi.org/https://doi.org/10.1016/j.jaap.2005.05.008>.

[xiv] Learner.