Diarylide Yellow is a semi-opaque, moderately staining, intense deep reddish yellow pigment with good tinting strength.
Diarylide Yellow 83 has very good lightfastness and permanence. However, it can fade in tints, so some artists do not consider it suitable as an artists' color. Many other diarylide yellow pigments are reported to have fair to poor lightfastness, and some are completely fugitive. Diarylide Yellow 83 is reputed to be one of the most permanent of the entire group.
Diarylide Yellow has no significant acute hazards, but chronic hazards have not been well studied.
Diarylide Yellow comes from a family of azo pigments called Diarylide. These yellow hued pigments were developed around 1940 and are very important in printing inks.
PY42-Yellow Iron Oxide
Fe2O3 • H2O
Yellow Ochre provides artists with earthtones from cream to brown. It has good hiding power, produces a quick drying paint, and can be safely mixed with other pigments. Its transparency varies widely from opaque shades to more transparent ones, which are valued for their use as glazes. If gypsum is present, Yellow Ochre is not suitable for frescoing. (See Brown Ochre, PY43.) PY42 is made from synthetic iron oxides. PY43 is made from natural iron oxide.
Yellow Ochre has excellent permanence because ochres are some of the most permanent pigments available.
Yellow Ochre is non-toxic unless it contains manganese.
Ochre comes from the Greek word ochros, meaning pale yellow. It was one of the first pigments to be used by human beings, and evidence of its use has been found at 300,000 year old sites in France and the former Czechoslovakia.