What is watercolour granulation?

Granulation is a textured, speckled effect caused by heavy pigment particles settling into the valleys of watercolour paper. Some pigments (like Ultramarine and Cerulean) granulate naturally, while others (like Phthalo Blue) produce smooth, flat washes. It is a desirable effect for creating atmosphere and texture.

Which pigments granulate the most?

The strongest granulating pigments include Cerulean Blue (PB35), Ultramarine Blue (PB29), Viridian (PG18) and Manganese Blue Hue. Mineral-based pigments tend to granulate more than synthetic organic pigments because their particles are heavier and larger.

How can I control granulation?

To increase granulation: use rough paper, more water, and let washes dry undisturbed. To decrease: use hot-pressed (smooth) paper, less water, and mix with non-granulating pigments. Granulation medium can be added to any colour to enhance the effect.

ArtCalcs

Granulation Chart Calculator

Calculate pigment granulation effects based on paper texture, water ratio and pigment properties.

PigmentPigment type affects base granulation

Paper TexturePaper surface affects pigment settling

Water RatioMore water = more pigment movement

TechniquePainting technique

How We Calculate This

Granulation Score

Each pigment has a base granulation score (1-10). This is modified by paper texture, water ratio and technique to give a final predicted score.

Modifiers

Rough paper and wet techniques increase the score. Smooth paper and dry brush decrease it. The final score predicts the visible granulation effect.

Frequently Asked Questions

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Last updated: March 2026

All calculations are estimates. Always verify quantities before purchasing materials.