Short for titanium dioxide, a pigment with a refractive index of roughly 2.5 to 2.7, so even a small amount scatters far more light than carbonate or clay. It goes into lightweight papers, decor papers for laminates and thin opaque grades where grammage cannot rise. It is expensive, absorbs UV that would otherwise excite brightener, and retains poorly unless the wet-end chemistry is right.
TiO2 is the priciest thing in the furnish, so if retention drops the accountants hear about it before we do.
Also heard as
- titanium dioxide
- tie-oh-two
Related terms
Filler
Fine mineral powder added to papermaking stock to raise opacity, brightness and smoothness and to cut cost.
Opacity
A sheet's ability to hide what lies behind it, expressed as a percentage from readings over black and white backings.
Quenching
Loss of optical brightener response caused by chemicals or materials that suppress its fluorescence.
Light-scattering coefficient
Per-grammage measure of how strongly a paper redirects light, written s and given in square meters per kilogram.