A plastic bag that contains milk. It is used as a packaging equivalent to milk cartons or plastic milk jug. In places in Canada where milk is commonly sold bagged, the bags are used by putting them into a small pitcher sized for the bag and then the corner of the bag cut to allow for pouring.
Small milk bags were introduced into US schools in the late 80's and early 90's, but fell out of favor. A common issue for kids was inserting the straw into the bag without spilling the milk.
