A class of white pigments, also known as transparent pigments, used to "extend" the quantity of other, perhaps more expensive color pigments, or to reduce a particular pigment's opacity, color strength, or other properties. Extenders are also used to increase the volume of an ink without altering its overall viscosity. See Transparent Pigments. In screen printing, an extender is known as an extender base.
In comouting, an extender is a device which increases the distance over which data can be sent from a computer to a printer.