A blind made up of a plurality of customisable rigid slats enables the blind to be fitted snugly within any window opening or doorway as a result of the locking adjustability of the width of such slats. The slats each include a pair of elongate slat panels movable relative to one another between retracted and extended conditions, such that the operative width of the blind is greater in the extended condition than in the retracted condition. The blind further includes one or more fasteners, located at or near each of a pair of minor ends of the slat panels, for releasably fixing the pair of slat panels to one another in the retracted condition, the extended condition and/or any condition there between, thereby to operatively restrict relative movement between the slat panels in such condition.