A sol is a colloidal suspension of very small solid particles in a continuous liquid medium. Sols are quite stable and show the Tyndall effect. Examples include blood, pigmented ink, cell fluids and paint.
Artificial sols may be prepared by dispersion or condensation. Dispersion techniques include grinding solids to colloidal dimensions by ball milling and Bredig's arc method. The stability of sols may be maintained by using dispersing agents.
Sols are commonly used in preparing sol-gels.
References
Sol (colloid) Wikipedia(Text) CC BY-SA