Argent

In engravings and line drawings, regions to be tinctured argent are either left blank, or indicated with the abbreviation ar.

The word argent had the same meaning in Old French blazon, whence it passed into the English language.

In some historical depictions of coats of arms, a kind of silver leaf was applied to those parts of the device that were argent.

This leaves a false impression that the rule of tincture has been violated in cases where, when applied next to a dark colour, argent now appears to be sable due to tarnish.

He bases this in part on the "white labels" used to differentiate the arms of members of the British royal family.