Titanium-Zinc White: Most useful all-purpose oil painting white. An excellent mixing white, T-Z White combines the soft texture and opacity of Titanium with the creamy transparency of Zinc for less "chalky" mixtures. Consider using T-Z White for color-mixing because it takes so much color to tint Titanium.

Pigment: Titanium dioxide, zinc oxide (PW 6, PW 4)
Vehicle: Alkali refined linseed oil
Lightfastness I, Series 1, OPAQUE

reference: www.gamblincolors.com