Those wearing cloth armour had best have some way to turn their offense into a better defense! The lightest form of armour before one can be considered naked, cloth grants a bare minimum of protection -- more from the elements than from blade or spell. At one time, many spellcasters of Sosaria and Britannia were bound by the strictures of their professions from wearing any armour heavier than cloth; the reasoning behind these early prohibitions are largely unknown in later times.
Peasant's garb for those who can afford nothing better, or those restricted by the vows of their profession from wearing aught else. A reluctant favorite among Magi.
Usually little more than a heavy quilted gambeson worn below a tunic, cloth armour is inexpensive and comfortable, but it affords only limited protection.