titanium dioxide
A white compound, the oxide of titanium (TiO
2 ). It occurs naturally in the rutile,
anatase, and brookite crystalline forms. The
rutile form is used in the manufacture of
pigmented paper coatings, while the anatase form
is used as a filler pigment in paper manufacture.
Both types (as used in papermaking) are important
because of their whiteness, high brightness, and
high refractive index (2.52 to 2.76), all of which
results in a paper of improved brightness and
opacity. (17 , 235 )