20 Microns Limited manufactures Silfermin - Nephyline Syenite. 20 Microns Limited is an ISO 9001:2000 awarded company. The company manufactures White Minerals of supreme quality, Functional fillers, Extenders and Speciality chemicals. The Silfermin - Nephyline Syenite is a specially designed extender to enhance the performance of paints, adhesives, sealants, ink etc. Tint retention and Weather ability can be achieved in exterior paints. Also Improves colour sheen uniformity, chemical and stain resistance, durability of interior paint formulations.