TiO.sub.2 -containing composite pigment products

Composite pigment products comprising from 4.5% up to 50%, by weight, of at least one particulate titanium dioxide;

• from 5% to 95%, by weight, of at least one low-refractive-index pigmentary extender;
• and from 0.5% to 10%, by weight, as determined by ashing, of an in-situ synthesized complex functional microgel cement, wherein the constituents of said microgel cements are:
• (a) from 0.5% to 10%, in relation to the total mass of said composite pigment, of a transient, chemically reactive subcolloidal hydrosol formed of
• (1) at least one reagent selected from the group consisting of alkali-metal silicates and quaternary ammonium silicates;
• and
• (2) at least one reagent selected from the group consisting of alkali-metal aluminates and alkali-metal zincates, the ratio of the reagents of (1) to the reagents of (2) being from 1:10 to 10:1, by weight;
• cross-linked by
• (b) at least one gel-setting agent selected from the group consisting of bivalent and multivalent inorganic salts in an amount of from 0.5% to 10%, by weight, in relation to the total mass to said composite pigment, and, optionally, at least one organic, cationically active chemical compound with two or more reactive groups in each molecule in an amount of from 0.001% to 0.5%, by weight, in relation to the total mass of said composite pigment, the ratio of said gel-setting agents to said chemically reactive, subcolloidal hydrosol ranging from 1:10 to 10:1 by weight.