The bright, harsh, high-altitude Winter-Sun shone through the windows of the apartment from three sides, and in the echoing emptiness I asked,

"What color would you like to make your painting?"

We had moved to this sunny third-floor apartment after a destructive wildfire-turned-urban-fire had destroyed part of our town and ruined nearly all of our belongings. Starting from almost scratch, we were building again. We hadn't been in our new place very long before Jonathan said he had wanted to make a painting-- a big painting-- a solid-color monochrome painting filled with impasto swirls of color. Before the fire, he had made some impasto work in Cobalt, and this was both a continuation of those studies and a departure-- a new beginning.

When I asked what color he'd like to make his painting, he said, "Ultramarine."

Ultramarine Blue is a blue that comes from a crucible, where very specific substances are heated together. We've read that applying heat to this pigment doesn't change its appearance-- it's a blue that is forged in the furnace. It is a blue of innovation, and a prize of 6,000 francs led to its discovery and modern production. Finally, is a blue of history, as its predecessor, natural lapis lazuli, is one of the lovliest natural stones on earth.

Ultramarine Blue is on my ultra-short list of essential pigments, and through my whole painting career, it is one of the colors which has always been included in the list of the most-prized colors on the palette.

In comparison to other blue pigments, Ultramarine Blue is:

• Closer to indigo-violet-blue than Phthalo Blue, PB15
• Clearer and more transparent than Cobalt Blue Deep, PB74
• Closer to violet-blue than Prussian Blue, PB27

PB29 or Ultramarine Blue is sometimes also named Ultramarine Blue Light, Ultramarine Blue Dark, or French Ultramarine. It is a blue pigment that is described as a deep gem-toned royal blue, and some varieties lean more or less toward a purple-blue (both varieties- the royal blue and the more indigo blue share the same pigment code). Ultramarine Blue is usually transparent or semi-transparent depending how the paint is formulated.

Modern ultramarine was borne from the dire need for a gorgeous, high saturation, deep royal blue pigment. The need was so great a prize was offered for its development.

Modern ultramarine blue is quite a complex innovation. Its chemical formulas are intricate and significant effort was put into its discovery. Lapis Lazuli had always been expensive and the method for extracting the lazurite was difficult.

In the older edition of his book (1970), Mayer wrote, "...Ultramarine was the most precious of artists' materials from the Middle Ages up to the early nineteenth century. Although azurite, blue verditer, and the other unsatisfactory blues were augmented by smalt in the seventeenth century and Prussian blue in the eighteenth, the invention of artificial ultramarine was one of the major events in the history of artists' materials."

According to Mayer, "accidental observation of a mysterious blue color encrusted as an impurity in the furnaces where soda ash was made," led to "intensive chemical research." Goethe made mention of the blue deposits around lime kilns in Italy in the late 18th century. A prize was offered in France to incentivize innovation. The winner was B. Guimet. More about its history and the twists and turns of its discovery can be found here.

A hundred years ago Uebele wrote, "Artificial ultramarine blue, while not as permanent as the natural, is on the lists of artists' tube colors, as it is when properly selected, deeper and more brilliant and very much lower in price."

Ultramarines come in a range of shades from greenish to reddish shades. Ultramarine Green is exceedingly rare as not to be really mentioned anymore, and it is most typical to find Ultramarine Blue. However, paints labeled Ultramarine Blue Green Shade are a rich deep blue. Within PB29 there are also deep blues that lean indigo which are sometimes labeled Ultramarine Blue French or Ultramarine Blue Deep. There is also a related pigment called Ultramarine Violet (PV15) which can range from indigo to middle purple to a reddish pink. Another related pigment which picks up in the reddish purples is Ultramarine Red or Ultramarine Pink made of pigment PR259. Here we focus on the range of subtleties within Ultramarine Blue, PB29.

Range of Colors for Ultramarine Blue, PB29 Setting aside Genuine Lapis, discussed above, there are two main subcategories of Ultramarine Blue. We'd call these regular Ultramarine or Ultramarine Blue Deep.

As in other areas of the blues, the red-green naming structure strikes again (e.g. Ultramarine Blue Green Shade is a deep clear royal blue while Ultramarine Blue Red Shade is a purpler blue that's usually a bit closer to Indigo). It's easier to imagine a color wheel with a handful of deep blues. Some versions of deep blue lean a tiny bit toward green, while others are a bit closer to violet. With ultramarine, the violet range stretches all the way to fully violet, and the pigment becomes ultramarine violet, PV15.

We've heard there are quite a few pigment options for paintmakers who wish to procure PB29 for their paints.

An antique book on paintmaking shows that even a hundred years ago or more there were many varieties of Ultramarine Blue for paintmakers to explore. Uebele wrote, "There being a dozen or so of grades listed, of which at least one-third will interest the color grinder for his various purposes, it is up to him to test samples offered him by the manufacturer for brilliancy of tone, shade, fineness, softness of texture, tinting power and clearness of tint produced with white. One part of the dry blue mixed with 25 parts French zinc white, rubbed out to the utmost is the best guide for this."

These days we don't tend to use zinc white for oil painting (or at least use it with caution) but it was one of the standard measures for doing a tinting test. Unfortunately we as painters don't have an easy way to determine the quality of the Ultramarine Blue which was selected by the paintmaker.

Ultramarine is legendary for being difficult to make into an oil paint. For oil painters, we enjoy the end results of all of the decades of R&D that paintmakers have put into homogenizing ultramarine into their paint lines. That said, many ultramarine paints with a nice consistency probably have an additive or stabilizer or two (such as a bit of beeswax). However we do not like to see aluminum stearate as it can cause other problems. Ultramarine in oil is naturally stringy, so some brands will modify it in various ways to give it more body.

For paintmakers, Wehlte notes that ultramarine is very hard to work with in oil. He writes, "When oil is added too sparingly, ultramarine will form a puttylike mass and may even start to burn in the roller mill. The color tends to become dull and lose its brilliance." He mentions that a particular resin may help but that it comes with its own sudden dangers. When adding the resin, "...the consistency may rapidly be reduced to a point where the paint runs. This break in consistency is reached quite suddenly. For this reason, a little beeswax dissolved 1:2 in turpentine is usually added." He concludes his remarks by saying, "Ultramarine is the most difficult pigment to grind by hand."

Elsewhere he wrote, "When grinding Ultramarine in oil or in some emulsions, one will find that the paint will long remain a dragging, puttylike mass. If more medium is added to remedy this, the material will suddenly start to flow off the slab. Different types of ultramarine vary in this respect."

Doerner wrote that, "About 2% wax is added to the color to make it "short" and also to prevent its hardening too quickly in the tube. One should allow the ground color to stand a day before putting it into the tube; the color then becomes thin again and is able to absorb more of the powder."

It seems that this may have been part of the inspiration for Rublev's particular take on Ultramarine which allows the pigment to rest between milling. Rublev's particular version (called Ultramarine Green Shade) is made with linseed oil. We've found it to be a fine paint, though be prepared for separation in the tube and for the occasional large amount of oil to come out when the tube is opened.

Odd or notable behaviors: There is something called Ultramarine Sickness which can happen to the paint film, but it is rare and may apply more to certain binding mediums. From a paintmaking perspective, Ultramarine is a notoriously difficult pigment to form into an oil paint and wax is often added in small amounts.

Wehlte remarks, "Unadulterated artificial ultramarine is one of the best glazing pigments available." Elsewhere he wrote, "Certain pigments like madder, ultramarine or viridian are very transparent by virtue of their crystalline structure. They are therefore called glazing colors. They should, more precisely, be called glazing pigments." He goes on to explain that naturally an opaque color can be used as a glaze if it is diluted enough. However transparent pigments like Ultramarine almost can't help but glaze.

In general, linseed oil forms the strongest paint films, however its drawback is a natural yellowing over time. The yellowing of linseed oil is more strongly felt in colors such as blue, purple, or white. For this reason, some painters may opt to have a version of ultramarine blue in a different binding oil.

However, other oils such as poppy and safflower have been known to experience drying problems of various kinds, and the circumstances under which the problems arise are not currently well-enough understood.

For general mixing throughout the layers of the painting, we opt for Ultramarine Blue in linseed oil.

Ultramarine blue is one of the colors where Poppy oil might be considered if it's used judiciously, thinly, and only in the topmost layer of a painting where the non-yellowing nature of the oil would be best appreciated by the viewer. However Mayer tends to think its non-yellowing reputation may be a bit overstated.

The theory goes that since linseed oil yellows naturally, colors like blue, purple, and white are prone to be affected by the effects of the yellowing, but authorities have mixed enthuisasm on whether poppyseed oil resists yellowing enough to outweigh its defects.

In general, Wehlte had rather neutral comments overall. He wrote, "Poppy oil yellows less than linseed oil, provided it has been obtained from white flowering plants by cold-pressing. Some commercial products look darker than linseed oil and yellow just as strongly." However we've heard from other sources (including Mayer) that poppy oil sometimes becomes tacky after it was thought to be dried, and may also be associated with other problems such as cracking. It also forms a weaker paint film.

Mayer wrote, "The serious defects of poppy oil are the frequency with which its paint films will crack upon aging, and its slow drying rate...." and he mentions the dangers of using it in multiple layers. It is sometimes mixed into linseed oil to extend the drying time of paints.

All that said, if a person wants the least yellowing oil, a high quality poppy oil paint may be worth the risk if used sparingly in the top-most layer of the painting.

Maimeri Puro makes both an Ultramarine Light and an Ultramarine Deep. In masstone, some paints labeled Deep are difficult to distinguish from regular Ultramarines, but the undertone is much more purple- leaning in tints.

Ultramarine is harmed by acids, so that is one thing to consider.

Older texts mention grades of ultramarine pigment, and that not all grades are suitable for artists' colors. They also mention that there should be no free sulfur in the ultramarine pigment. Sulfur can also react with other pigments.

Doerner cautions, "Unfortunately this beautiful and valuable color becomes quickly discolored by the action of weak acids, which attack it, forming hydrogen sulphide. Vinegar, which is often used with tempera, and also carbolic acid used as a disinfectant, can by their continued action, even in very small quantities, completely ruin this beautiful blue color in a picture. Alum will likewise discolor ultramarine." This is getting technical, but Doerner even mentions that "Free acids in the very fat oils may do the same."

Ultramarine is generally regarded as the category of Low Concern. There are usually no listed hazards, however reference the note from CAMEO. As with all pigments, do not breathe the dust.

We were surprised to refer to a toxicity note on CAMEO on natural lapis lazuli, which is chemically similar.

For toxicity information, refer to manufacturer SDS. Treat all pigments and paints with studio safety protocols.

PB29 pigment data from David G. Myers, The Color of Art Pigment Database, Artiscreation.com

Information about PB29 from Bruce MacEvoy, Handprint Guide to Watercolors, General information about this class of pigments from Handprint

CAMEO Materials Database: Conservation & Art Materials Encyclopedia Online, Museum of Fine Arts Boston. (Accessed June 2043). Ultramarine Blue, Synthetic https://cameo.mfa.org/wiki/Ultramarine_blue,_synthetic. Museum of Fine Arts Boston.

Alfa Chemistry (n.d. Accessed June 2025). Ultramarine Blue (PB29) https://materials.alfachemic.com/major-products/ultramarine-blue-pb29.html,. Alfa Chemistry.

Ambrose, Trevor (2023, September 24). ASTM Lightfastness Testing for Oil Paints https://justpaint.org/astm-lightfastness-testing-for-oil-paints/. Just Paint, Golden Artist Colors.

Douma, Michael, curator, Pigments through the Ages. 2008. Institute for Dynamic Educational Advancement. (Accessed December 2025). Ultramarine Blue https://www.webexhibits.org/pigments/indiv/history/ultramarine.html.

Doerner, Max. The Materials of the Artist and Their Use in Painting with Notes on the Techniques of the Old Masters. Harcourt Brace and Company New York, 1949. https://archive.org/details/materialsofartis0000maxd

Mayer, Ralph. The Artist's Handbook of Materials and Techniques. New York, Viking Press, 1970. Internet Archive, Web. Accessed August, 2025. https://archive.org/details/artistshandbooko00maye

Mayer, Ralph. The Artist's Handbook of Materials and Techniques, 5th ed. New York, NY, Penguin Group, 1991. https://amzn.to/44OzBN9

Wehlte, Kurt. The Materials and Techniques of Painting, With a Supplement on Color Theory. Van Nostrand Reinhold 1975. https://amzn.to/3Gutt3l

Article written by Melissa Carmon

About the author: When a sudden urban firestorm threatened their studio, Melissa and her husband Jonathan rescued The Great Book of Color, about 800 pages of her handwritten notes gleaned from her years of painting. They co-founded the Paint List to empower fellow painters around the world. More can be found here. Read More.