The pigment code PBr7 covers a huge part of the traditional painter's palette. Welcome to the wild domain of one of the most confusing (and the most common) pigment codes in oil paint. To make matters even more interesting, the historical paint names of the past describe genuine earth colors that have become very hard to find.

In the realm of PBr7, the pigment code may not help a painter very much to navigate the terrain. In every other area of the palette it seems the pigment code will be more helpful than it is here. In this land, we are going to have to find different guides-- we will have to turn to old books, and consult sources which seem to have been long-forgotten.

In modern times, we are often told as painters that the famous names given to these earths, such as Burnt Sienna, are arbitrary, and that paintmakers can call them whatever they wish. What they don't say is that there is actually a rich lost history from artists of the past-- a language painters developed to describe the attributes which they expected from their paints.

In many other areas, pigment codes can help to identify materials. However, since PBr7 is such a broad pigment code (for example, a painter may well have a use for more than one PBr7 on their palette), the color names within it take on greater importance. The code PBr7 encompasses earth tones that exhibit a reddish brown, a tepid green, a golden ochre, or a deep chocolate brown umber.

To make matters more complicated, the historical color names used by painters are sometimes shared by multiple pigment codes. For example, some Raw Sienna paints have a pigment code for yellow earth, PY43, while others are PBr7. Similarly, some Burnt Siennas are labeled as red earths, PR102, while others are brown earths, PBr7. When it comes to earth tones, pigment codes don't give artists quite enough information.

Most of the time, a pigment code gives artists a lot of good information about their paints. Unfortunately, PBr7 is the most common pigment code for single-pigment paints and it also gives us the least color information.

When we think of PBr7, we usually envision brown earths, but the color can spin out to yellow, to green, to red, or even to violet from there. Granted these are brownish reds, greens, yellows, and violets, but for a painter purchasing colors the category is too broad to be helpful.

PBr7 is one of the pigment codes that does not give a person a lot of color information, besides the general tendency of earths toward a middle chroma. It's possible to find a few relatively cooler browns and even a stray green or two. Natural Brown Iron Oxide, PBr7, has several well-established sub-variants. Some of the more frequently occurring names are Umbers and Siennas. Umbers tend to be darker brown while Siennas at least start out a little bit lighter. Raw Sienna and Raw Umber can be burnt or calcined to make Burnt Sienna and Burnt Umber, which tend to be warmer than the raw colors. The names often add a place of origin such as French, Italian or Cyprus, though unfortunately that is not a guarantee that the earth tone came from that locale.

Related pigment codes are PR101 and PR102 for red earth (synthetic and natural), PY42 and PY43 for yellow earth, and PG23 for green earth.

Raw Sienna: tends to be a warm gold color or a yellow-brown that has a bit of an orange note when mixed. It's often a bit oranger or deeper than Yellow Ochre. Raw Sienna is named for the earth color which was mined in or near Siena, Italy, and the genuine earth tone has some native transparency. This color is sometimes listed under the pigment codes for yellow earth (PY42 or PY43). Natural impurities may contribute quite a bit to the desirability of genuine Raw Sienna, as they make the pigment semi-transparent. The warm note makes it a useful color in portraiture.

Burnt Sienna: A deep red brown that is one of the quintessential artist's colors. From flesh tones to landscape to abstracts, this radiant warm brown is everywhere. If brown could be a gemtone, that's what we think of with some of the best Burnt Siennas. The same paint name is also found among the red earths (PR101 and PR102). Burnt Sienna is a warm middle brown which often shows rosiness in tints--a brown and a red at the same time. Burnt Siennas range from transparent to semi-opaque, however it is also possible to find opaque versions. Natural versions (PR102) are often named French or Italian depending on their origin and may have a larger variety of particle sizes. Burnt Sienna is made of calcining or heating Raw Sienna hence the name "Burnt". It has a medium to fast drying time, though not as fast as the umbers. Older authors praise its beauty, prize the deep mahogany versions, and mention that it is not chalky in mixtures. It's ideally transparent or semi-transparent.

Burnt Umber tends to be a dark chocolatey brown that is warmer than Raw Umber. It is made by heating various earths or calcining them, which yields a deeper and redder tone. Some burnt umbers have a bit of transparency (semi-opaque) while it is also common to find opaque ones. The umbers sometimes have problems with a phenomenon called sinking-in. (More on this in the section on Burnt Umber). This is a pigment that tends to require a lot of oil but is also a very fast drier, possibly due to Manganese. We noticed a comment in The Artist's Handbook by Pip Seymour where the author wrote, "Because it darkens appreciably in oil use carefully". More on this below.

Raw Umber tends to be a cooler dark brown that may even have a very faint green leaning to it depending on the variety. For example, some Italian Green Umbers are raw umbers that are especially cool. The transparency varies. Among the green umbers some semi-transparency (as well as low tinting strength) is common, but other Raw Umbers may be opaque.

Raw umbers can vary from pale browns, tepid greens, or deep rich browns with a cool note. While we wish the earth tones would be single pigments, sometimes Turkey Umber has a note of added green (we've seen a few with PG7 mixed into it).

Raw Umber requires a high amount of oil, and can also be associated with "sinking-in" in oil painting (similar to Burnt Umber, mentioned above), so it is helpful to understand the causes and plan one's painting accordingly.

Umbers often contain manganese. Please see Monona Rossol's work for information about health hazards associated with manganese. This metal speeds drying, so despite high oil content, umbers are among the very fast driers. Some of the natural varieties have a degree of transparency.

Other names include Cassel Earth, Italian Earth/Italian Umber, and Brown Ochre.

We have been amazed to read the descriptions of the earth tones from past centuries. Our inquiry into this so far has shown that there is some merit to the claim that older earth tones used to be different, and that perhaps due to expense, perhaps due to scarcity, or maybe having to do with the synthetic iron oxide market, things have changed.

The cannon of literature from the past helps inform us as to what was expected from the earth tones available at the time. We will examine each pigment in turn, beginning with Burnt Umber. It seems that back then there was a variety available which was olive with a tinge of violet in tints.

Burnt Umber is a single-pigment earth tone, and the best versions were burnt Cyprus Umber or Turkey Umber. An author from over a hundred years ago writes, "It runs from light reddish brown to a violet brown, its tone depending upon the nature of the raw material it is calcined from. The roasting or calcination...imparts a warmer tone, deeper color and more translucency to the pigment."

In general, Burnt Umber would ideally have a very similar composition to Cyprus Raw Umber (described below), from which it should ideally be made. "Burnt Turkey umber with a reddish brown tone makes a stronger stainer, but the pigment with a neutral tone that leans, when ...in oil, to the olive with a tinge of the violet and produces when used with white a tint that has a suspicion of lavender-gray with its drab effect, is far preferable to the almost terra cotta brown tint produced by some of the reddish toned burnt umbers."

In 1913, Charles Uebele wrote that, "The best undoubtedly comes from the island of Cyprus." He went on to say, "The best quality of Cyprus raw umber has a peculiar greenish cast, which we usually term olive, and its color is due to ferric oxide of iron and quite a large percentage of dioxide of manganese, to which latter is also due its good drying quality when ground in linseed oil. Some specimens have a somewhat dull reddish or yellowish cast. These, however, produce a poor tint with white. The olive toned raw umber, makes a much warmer tint and is especially favored by artists..."

When compared with the best sample of American Raw Umber available at the time for analysis, he said, "This specimen of American raw umber ...in oil had a yellowish brown tone, as against the olive of the Cyprus umber and lacked the semi-transparency of the latter, as well as its richness. Had a dull appearance in comparison, that a practical painter would describe as having "no life." In testing the staining power or strength for staining white, the Cyprus specimen gave a strong, warm, brownish tint with a tinge of green, while the American umber produced with the same white a weak, cold stone gray." For some artists that neutrality may be a boon in mixes, but the Cyprus umbers clearly had a different quality. He gave detailed notes on the chemical composition of each specimen. Later, he goes on to say, "For artists' tube color only the very warmest olive toned raw Turkey umber should be selected and ground very fine..."

Another antique source mentions that "the brighter and redder toned siennas are much preferred and command the higher price." In 1913, Charles Ubele wrote, "The brightness of tone does not depend entirely upon the temperature and length of time used in calcining, but to a greater extent upon the quality of the natural earth. The so-called red fire burnt siennas, so highly valued for their brilliancy of tone and richness of tint, that were imported years ago from Italian sources, are hardly met with now, excepting in rare instances, due, it is said, to the mines being exhausted, which may be partly true, but it is also a matter of fact that the average manufacturer will not pay the price asked, when the consumers themselves look more for tinting strength, than for transparency and brilliancy of tone."

Ubele also mentions the importance of the absolute freedom from grit in the selection of pigment for Burnt Sienna: "As mentioned in the case of raw sienna for artists' tubes, only the old time standard of material should be selected in burnt sienna as well and the more brilliant the overtone of the pigment, the more favorably the color will be received by the user. In grinding burnt sienna for the artist, extreme care for obtaining the highest degree of fineness and absence of all grit must be exercised..."

The famous Terre di Siena or Raw Sienna is a yellow-orange-brown color interesting pigment which is not always well-enough differentiated from Yellow Ochre in some modern paint lines. In fact, while some brands have a nearly indistinguishable Yellow Ochre and Raw Sienna, we have also noticed a wide range of colors that are sold as "Raw Sienna" across paint brands.

Old painter's books from the past speak of a Raw Sienna pigment that is both deeper and more delicate than Yellow Ochre. This pigment had native transparency due to impurities in the clay from which it is mined. It is also a bit warmer than a Yellow Ochre, and may have an orangey note.

Raw Sienna should be less opaque than Yellow Ochre. An older text mentions that it contains Iron and Manganese, while in a newer version of the same book, the manganese note was dropped.

An interesting note from a paintmaker's perspective is that Raw Sienna doesn't really require any additives or stabilizers to form a lovely paint.

Many Raw Siennas are PBr7, but some are also PY43.

Several other names are found with some frequency among PBr7 paints.

Cassel Earth (Hue) or Van Dyke Brown (Hue). Names and pigment codes can get a bit fuzzy here, but it seems that the Van Dyke Brown labeled as PBr7 is probably a kind of umber that looks like Van Dyke brown. NBr8 is the pigment code for Van Dyke Brown (also sometimes called Cologne Earth or Cassel Earth, which may be a particular variety). Genuine Van Dyke Brown NBr8 contains lignites, and has some amount of vegetable matter (e.g. peat or decayed organic matter) which causes it to fade somewhat over time. We associate genuine Cassel Earth/ Van Dyke Brown with nearly neutral mixes with white. The genuine NBr8 we've tried was fairly gritty.

Green Umber or Raw Umber Cool. It's fairly common to find Raw Umbers that have a green leaning or a bias away from the warm oranges and reds. Natural Bohemian Green Earth, Italian Green Umber, Turkey Umber, or Cyprus Umber Green are some of the names associated with a cooler (or even more neutral) umber. Other green earths may be found under pigment codes PG23, Green Earth, or even under PY43, which is for the Yellow Earths.

Red Earth Old Holland, Vasari, and Williamsburg all offer a Red Earth paint that is PBr7. Other paint names include Cyprus Umber Red, Red Brown Vayk, and Sardinian Red Earth. For more red earths, check out pigment codes PR102 and PR101.

Brown Ochre and Brown Ochre Light Includes the Brown Umbers, and Italian Brown Ochres. We'd tend to associate them with more opacity but that's not always a given.

Natural Brown Iron Oxide, has excellent lightfastness-- generally thought to be among the most lightfast.

There was a really interesting quirk that turned up in Golden’s Lightfastness Testing in oils. We don't have a lot of information but one Raw Umber revealed a slight sensitivity to Flake White in linseed oil, though this may be particular to that exact pigment source.

In general PBr7 performed at the expected ASTM I. There are many forms and colors within PBr7 and we would expect them to perform at ASTM I as well.

Earth tones vary a lot in particle size. We've seen a few comments in old books on paint manufacturing that grittiness was not a desirable trait. Many modern paintmakers will spin grittyness as a positive feature and praise the "larger particle size" however we hear from a lot of painters that they do not like grit. So to each their own.

Years ago we attended a Williamsburg demo at an art supply store where they showed the varying levels of grittyness in their paints. We wish more brands would publish information about their particle sizes as well as charts to organize their colors. Williamsburg's chart may be found here. We actually wish they would add another level of categorization, as many of their natural earths (Italian, French) do have some audible grit to them.