Colloidal systems are important across a range of industries, such as the food, pharmaceutical, agrochemical, cosmetics, polymer, paint and oil industries, and form the basis of a wide range of products (eg cosmetics and Measurement of surface forces (chapter 16), by Wuge Briscoe. A new contributor, David Fermin will update chapter 2 on Charge in Colloidal Systems, which was originally written by Jason Riley.