This invention discloses an apparatus for separating differing vertically orientated containers (11, 12), particularly for use in manufacturing operations. The apparatus includes at least one pair of parallel guides (10) substantially aligned in a direction of travel of the containers (11, 12). The pair of guides (10) are operatively positioned to receive the containers (11, 12) therebetween. The distance (W) between the pair of guides (10) is between but not equal to the largest and smallest diameter or width of the containers (11, 12). There is also disclosed a method and apparatus for stacking containers employing the separation apparatus.