Ocher, the oldest color
Ocher is a truly ancient pigment. Already during the early Stone Age in Africa it has been used. Archaeologists have found evidence of the use of red ocher before humans were homo sapiens 300,000 years ago. Neanderthals also used ocher. The pigment is therefore very old and is the same today as before, namely hydrolyzed iron oxide for the yellow variant and more iron oxide the redder the colour.
The difference between modern and original ocher is the fact that the original has arisen through natural processes while the modern is synthetically produced.
Different types of ocher
For the vast majority of watercolor painters, and certainly also other artists, ocher is just a yellow-brown color that is slightly opaque and quite clear in tone. But all possible earth colors with different appearances are actually ochres, even if they sometimes have other names. There are hundreds of different names for ocher with different origins and characteristics, here are the most common:
- Yellow ocher. This is the most common type, it is included in almost all ready-made watercolor sets. The color is usually fairly clear yellow and only slightly unclear. It is often opaque but can be a little more transparent. The variation between different manufacturers is very large.
- Gold ocher is slightly darker than the yellow variant, sometimes even a little more orange.
- Red ocher is originally a pigment that contains more or less amount of hematite (iron oxide). It can also be burnt to achieve the red tone.
- Sienna is an ochre, originally from the area around Sienna in Italy. The pigment contains a little manganese oxide, which makes the color slightly darker and more unclear. The pigment was sought after because of its transparency, so even modern sienna is made more transparent than other ochres. A burnt, redder variant is also available.
- Umbra is another ocher that contains manganese oxide. The amount of manganese oxide is greater than in sienna, so the color is darker and more unclear. Umbra is also available in burnt form, which is darker and more red.
- Iron red is usually the name given to different ochres with a high iron oxide content. Examples of such colors are Indian red, English red, Venetian red and caput mortum. All these colors contain iron oxide or hematite to a higher or lower percentage of the pigment.
Therefore, almost all yellow and red earth colors are different types of ochre. It’s just that we have given different names to the different variants. The color tone can be radically different in different types of ochre. From just a little unclear lemon yellow to almost black violet.
An important reason why all major manufacturers have abandoned natural pigments and switched to synthetic ones is that the natural ones vary in color tone and other properties. It is very difficult to maintain the exact same color with a new supply of pigment. The natural pigments vary in appearance, while the synthetic ones are always the same as before.
The reason why a modern yellow ocher is more opaque and a brighter yellow than, for example, a raw sienna is simply the fact that the originals have these qualities. The paint makers could very well make a transparent yellow ocher but choose to make it opaque because it better mimics the original color.