Ultrafine calcium silicate: CaSiO₃, calcium silicate made from wollastonite has needle-like structure, good brightness and very low oil absorption, suitable for oil-based house paint, flat or semi-gloss interior paint and latex paint. Its pH is about 9.9, and it can act as a buffer in latex paints under alkaline conditions.

Synthetic calcium silicate is a kind of hydrated calcium silicate, which is obtained by hydrothermal reaction of diatomite and lime. The grain shape can vary from "circular" to needle-like. The average particle size of all varieties is 1.6 to 3.8 μm, which belongs to the colloid range. The preferred variety is white. This type of filler has superior performance than diatomaceous earth, and its extremely high oil absorption means it has strong matting ability and high dry hiding effect. The proportion of application in coatings is not large, only 10% of the total amount of fillers. It has an exceptionally high water absorption and is recommended for latex paints.