The use of de-inked newsprint is expected to grow rapidly in Canada over the next five years. The de-inking process employs alkali to remove the ink and therefore provides the ideal environment for the use of hydrogen peroxide as a brightening agent for the furnish. This paper outlines the basics of the chemistry of the de-inking of newsprint and discusses the optimum use of hydrogen peroxide in these systems. Principles for application of peroxide are illustrated by laboratory data simulating de-inking conditions.