Cargille has been serving microscopists since 1940 when it introduced the first non-drying immersion oil formula. Since then, they have continued to improve and expand their line of immersion oils to become the undisputed leaders in immersion oil technology. Oils are available in a number of different formulations and can be readily mixed to create intermediate viscosities as required. Types B offers a viscosity of 1250 cSt, and is used in normal light microscopy. The viscosity B type is used as the gap between the cover glass and objective or condenser and slide increases.