• Very expensive and are not used in paints for ordinary purposes.

#### *5.2.3 Red pigments*

These are one of the oldest-pigments. They are mainly used for inhibiting rusting of iron and steel structures. The composition, properties and applications of these can be summarised as follows:

#### *5.2.3.1 Red lead*

It consists of Pb3O4 and PbO, used for a primary coat on structural steel and in imparting red colour to the glass for making bangles.
