Once upon a time some of the finest natural ochres had depth and transparency. Luckily some of these qualities are found in the modern synthetic versions. The tradeoff with synthetic versions are a softness that is often only found in regular yellow ochres. We love both for different purposes.

Synthetic Yellow Ochre and Mars Yellow earths have different pigment codes than the natural earthtones. Synthetic ochres are labeled PY42, while the natural kinds are PY43. This is a pigment code with a ton of variety in color and particle size. The synthetic earths are generally more intense than the natural ones, and it’s common to find paint names like Transparent Yellow Oxide or Mars Yellow. Colors extend into the oranges and browns so there is a variety of colors that are found within PY42. These tend to be extremely lightfast and reliable pigments, though Bruce MacEvoy found some anomalies in watercolor.

There is a disturbing trend in the paint world wherein earthtones are being emulated by a handful of pigments. Such imitations will not have the handling and permanency of iron oxides.