Colored cellulosic casing with clear corridor

A sausage casing comprising an elongated cellulosic tube having less than about 100 wt. % moisture based upon the bone dry weight of cellulose and having first and second longitudinal portions, and a colorant or opacifier which is longitudinally and continuously dispersed throughout the wall of at least one of these portions to provide it with different optical properties which are useful e.g., for quality control and identification of color development, meat type and particle definition and/or to provide an attractive package appearance. In a preferred embodiment, a sausage is encased where the surface area of the second portion is less than or equal to the first portion and these portions are visually different having measurable L,a,b and opacity values such that:i) an average opacity value of the first portion is at least about 0.5 greater than that for the second; orii) the difference in average opacity between the first and second portions is less than 10, and a difference of at least about 5 exists between the first and second portions in their L,a, or b values; oriii) there is a difference of at least about 10 in average opacity between the first and second portions, and the sum of the absolute values of a and b of the first portion is at least 10.