Calcium Carbonate OMYA BL OG Calcium Carbonate. Since the demise of BLR 2 by Omya, probably the best carbonate filler in the world, we have been seeking something to replaced it. So far this is the closest by far! A regulated 300 mesh carbonate, this has had some of the fines removed, so less impact on your viscosity.
Where regular french chalk will create viscosity penalties at as little as 10%, this carbonate can be added at up to around 40% before major impact on viscosity. However its not as good as BLR2!