Abstract: A carton comprises first and second rectilinear side walls which are hingedly connected together along one of each of their edges. A third side wall structure, which may comprise one or more individual walls, is hingedly connected to second edges of the first and second side walls. The carton is completed by opposed end walls which are connected to the second side wall and to the third side wall structure, but not to the first side wall. A tear line extends across the second side wall to both ends of that wall's connection with the first side wall. When the tear line is severed, the first side wall and a portion of the second side wall are disengaged from the other portion of the second side wall. Additional tear line structure is provided in the second side wall between the first tear line and the remaining two corners of the second side wall, whereby the carton may be open flat when the tear line 4-structure are severed.