White Bentonite for Ceramics: Raw Whiteness vs. Fired Colour

White bentonite can attract interest from ceramic manufacturers seeking functional clay additives with limited impact on product appearance.

However, the colour of the supplied powder and the colour of the fired ceramic are different properties. Both deserve evaluation.

Measure Raw Whiteness Consistently
Whiteness results depend on the measurement method and sample preparation.
When comparing suppliers, identify the instrument, reporting scale, sample moisture and preparation procedure. Values from different optical methods should not be treated as directly interchangeable.

A photograph is useful for initial communication, but lighting and camera settings can change the apparent colour.

Examine the Chemistry
Iron, titanium and other constituents can influence ceramic appearance. Their effects depend on concentration, mineral form, the complete formulation and firing conditions.

Commercial low-iron bentonite products exist, showing that colour-sensitive applications can require more than a general white appearance. BYK describes its BENTOLITE range as natural bentonites with low iron content.

Total chemical analysis should be considered together with the potential presence of localized particles that could produce visible defects.

Test the Actual Ceramic Formulation
Fire a control formulation and candidate additions under the same conditions.
Use the intended temperature, atmosphere and firing cycle. Record colour, visible specks, shrinkage and relevant physical properties.
A pure-clay firing sample can provide supporting information, but it does not reproduce the behaviour of a small addition within a ceramic body.

Connect Colour with Functional Value
The selected grade should also meet the formulation’s requirements for workability, strength or slurry behaviour.

A successful evaluation identifies an addition level that delivers the required processing benefit while maintaining acceptable fired appearance.

HERMANO offers natural white bentonite for application testing. Provide your ceramic formulation type, firing conditions and colour requirements to discuss suitable sample evaluation.