For the manufacturers of papers and paperboards new opportunities are opened up by pigments with a tight control of particle size and size distribution, and by their specific interaction with UV/Vis-light.

A new barium sulfate-based product offers specific advantages in the manufacture of high-quality coated papers and paperboards for packaging of food & beverages, cosmetics, drugs or cigarettes. The use of this pigment provides a significant improvement in gloss, surface smoothness and printability. SEM/EDXA, Scar index and dynamic penetration experiments revealed the origin of this phenomenon: The fine structure of the surface topography is optimized by the combination of kaoline/barium sulfate.

In addition, a diffusion of the fine particle sized BaSO4 into the precoat reduces the capillarity of the precoat and improves a controlled ink setting. As a result, higher colour brilliance and less mottling are technical features of the printed final products, and on the economical side, customer's manufacturing costs may even be reduced considerably.

A different approch is heading towards the whiteness of coated papers: Titanium dioxide and optical brighteners compete with each other in their absorption of UV light. At the end, the performance of both is suffering: The optical brighteners are less effective due to a lower rate of excitation, and the overall impression of the paper is flatter than expected by the use of TiO2 An alternative is to combine the optical brighteners with white pigments which do notabsorb UV light. As possible concepts, both barium sulfate- and zink sulfide-based products could be used as white and pure, synthetic materials of neutral colour.