Transparent Brown Oxide PR101

Transparent Brown Oxide

Brown Oxide or Brown Iron Oxide is a color that several different manufacturers have in their respective ranges. This text is mainly about the paint from Daniel Smith which has the name Transparent Brown Oxide, of course this paint shares several characteristics with the same paint from other manufacturers but details can differentiate.

This is the first post on a series of paints from Daniel Smith that are all transparent and made from synthetic iron oxide. The others in the series are Transparent Red Oxide, Transparent Yellow Oxide. As well as the environmentally friendly colors EnvironOxide.

The pigment is PR101, which is synthetic iron oxide, it is a pigment with rich possibilities for variation. The pigment can be very opaque and reddish, then it becomes paints such as light red, Indian red, Venetian red, Caput Mortuum and other so-called Mars red colors.

It can also be very transparent and orange in color, giving it names such as burnt sienna, Red Iron oxide and red oxide. There is also synthetic hydrated iron oxide which is yellow in colour, this has the index name PY42 and is used for Transparent yellow Oxide.

Different variants of PR101 and PY42 are achieved by varying the size of the pigment grains, different metallic additives and hydration.

Daniel Smith has three colors called Transparent Oxide, namely brown, red and yellow. Three more other colors they call “EnvironOxide” which are made from recycled iron oxides from the drainage of abandoned mines. These are also available as brown, red and yellow.

The first color covered here is Transparent Brown Oxide which is a dark brown color similar to burnt umber. The color is very lightfast and intensely dark brown in hue. Daniel Smith has tried to make the pigment granulate, all the colors in the series are listed as granulating. Something that hardly distinguishes the pigment PR101 in ordinary cases.

The granulation is a bit strange, usually what is meant by a granulating color is that the pigment grains are heavier and often also have a tendency to clump together, so that they sink quickly in the water, and collects in all the little dimples in the paper. This gives a grainy impression and the paint is then said to granulate.

But Transparent Brown Oxide does not form such a grainy surface, but rather the pigment collects in threads. This effect appears mainly in fluid painting, and becomes more apparent if you paint in a way that would have made a “normal” watercolor color bloom, Transparent Brown Oxide does not create blooms, it instead becomes stringy.

But the most surprising feature of this paint is how much it changes color between wet and dry.

Newly painted Transparent Brown Oxide
This is what it looks like when it’s dry

The difference between wet and dry paint is extremely large. So big that I don’t think it’s possible to mix a balanced mixture with this paint, the mixture you create with any other paint will look radically different when the paint dries.

The pictures below show how much the color changes in a mixture. This is Transparent Brown Oxide mixed with Phthalo Blue. While the paint is still wet it is clearly green, but in the dried state the green tone has completely disappeared. It has been replaced by a grey-brown weird color, Notice how the two colors separate, it’s not the blue color that causes this, it’s the brown that separates from the blue and gives this weird pattern.

A green mixture with Phthalo Blue
Same color mixture dry.

Transparent Brown Oxide is thus a dark brown color with wacky properties. When wet it is a beautiful dark reddish brown. When it has dried, the nice red tone has disappeared and been replaced by an equally nice, but more grayish dark brown. Color mixtures turn out to be different than you have imagined. The color lacks the ability to bloom, it forms a stringy pattern instead.

A fun color that could be very useful, but not suitable for precision painting. It is more of a color when you paint roughly, and let chance decide the result.

Transparent and dark brown
Not very staining
No back-runs but gets stringy
The paint is not very willing wet in wet
Not really a hard edge.


Color index name: PR101
Lightfastness: Excellent
Transparency: Transparent
Staining: No
Granulates: Yes (sort of)

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