French Ultramarine vs. Ultramarine Blue (Green Shade): What’s the Difference?

Ultramarine is a staple in many artist palettes—but did you know there’s more than one kind? Two of the most common variations are French Ultramarine and Ultramarine Blue (Green Shade). Though both are made from the same pigment, PB29 (Sodium Sulfosilicate), their differences in tone and behavior can have a significant impact on your artwork. Here's what you need to know to choose the right one for your palette.

Same Pigment, Different Hue

Both paints are made from the same pigment, PB29, but they are manufactured or processed differently to shift their undertone and appearance. This results in variations that artists often classify as red-biased (French Ultramarine) or green-biased (Ultramarine Blue GS).

French Ultramarine

• Undertone: Warm, reddish-blue
• Appearance: Rich, velvety, often leans toward violet or purple when diluted
• Granulation: Strong granulation, great for texture and atmospheric effects
• Best For: Skies, shadows, expressive or moody colour schemes, mixing purples

Ultramarine Blue (Green Shade)

• Undertone: Cooler, greenish-blue
• Appearance: Slightly brighter and cleaner than French Ultramarine
• Granulation: Moderate to strong granulation, but typically less dramatic than French Ultramarine
• Best For: Water scenes, foliage, clean blue mixes, neutralizing warm oranges

Why the Shade Difference Matters

Though the difference may seem subtle in the tube, it becomes more apparent when mixing and painting. French Ultramarine's warm undertone makes it ideal for mixing with reds and earth tones, while Ultramarine Blue (Green Shade) leans cooler, making it a better match for cooler colour schemes and cleaner secondary mixes.

Mixing Comparison

• With Alizarin Crimson or Quinacridone Rose: French Ultramarine yields vivid purples.
• With Hansa Yellow or Lemon Yellow: Ultramarine Blue GS creates more balanced greens than French Ultramarine, which can gray out the mix slightly.

Which Should You Choose?

There's no one-size-fits-all answer—many artists carry both! But here's a general guideline:

• Choose French Ultramarine if you love moody skies, strong granulation, and rich purples.
• Choose Ultramarine Blue (Green Shade) if you want cleaner mixes, a more neutral blue, or are working in a cooler palette.

In Summary

While both French Ultramarine and Ultramarine Blue (Green Shade) use the same pigment, their subtle differences in warmth, granulation, and mixing behavior can significantly affect your painting. Understanding these nuances allows you to make more intentional choices—and unlock the full potential of ultramarine blue in your work.