PY 139 – isoindoline yellow

Manufacturer/ product code:  Kremer / 24000
Chemical Description:  isoindoline
Color: yellow
Color Index: PY 139
Date:  from 1964

PY 139 – Isoindoline Yellow is a synthetic organic pigment belonging to the isoindoline family, known for its bright, clear yellow hue, excellent lightfastness, and chemical stability. It is widely used in both artistic and industrial applications due to its high chromatic purity, durable performance, and versatile mixing properties.

Chemically, PY 139 is based on an isoindoline molecular structure, which consists of fused aromatic rings with nitrogen atoms stabilizing the chromophore. This structure provides outstanding resistance to light, heat, and solvents, making the pigment suitable for a broad range of media including oil, acrylic, watercolor, inks, plastics, and coatings. Its chemical robustness ensures long-term color retention and minimal interaction with other pigments or binders.

In artistic applications, Isoindoline Yellow exhibits strong tinting strength and semi-opaque to transparent properties depending on particle size and formulation. Its clean, slightly warm yellow blends well with other yellows, reds, and whites to produce a wide variety of warm hues, from bright golden tones to muted pastels. Its transparency also enables glazing and layering techniques, providing depth and subtle modulation in painting.

From a conservation perspective, PY 139 is highly inert and resistant to fading, maintaining its brightness and chromatic purity over extended periods. Its stable chemical behavior ensures minimal degradation, even in mixed pigment systems.