Once use of non fibrous material in paper making was considered to be cheating on the customers. This was so for many years. The effect of fillers on paper not only gives certain improved optical properties on paper but also reduce the dependency on fibre. In the initial days filler mean invariably of soap stone powder (Talc) used in paper making. The limitation was imposed due to acid size during the period. The ash percentage on paper also could not be increased above 4 to 6 % on paper and this achieved at the reduced strength of paper. With the advent of alkaline sizing, the usage of precipitated calcium carbonate and ground calcium carbonate ash on paper is increased paper to the tune of 18 to 20%. This increase in ash on paper without affecting the paper strength and at the same time increases the optical properties of paper. The increase in optical properties of paper cannot be without some of draw backs in the form of fast wear out of forming fabric particularly wire.
