In the paper industry, Precipitated Calcium Carbonate (PCC) is used to improve the wood fibres adding mineral fillers and additives to stabilize and give the paper consistency, which is obtained after the final drying. PCC is used as a filler to increase the volume and porosity of the paper, while providing whitening levels and a significantly higher opacity to those obtained through non-synthetic fillers. Thanks to above features, CALPREC PA® is specially recommended in low weight papers which need opacity.