Abstract: This invention relates to a display box of the kind comprising a part of an opaque material such as cardboard and an opening overlapping or straddling at least one edge of the box and which is shut off by a sheet of a plastics material. According to the invention the sheet is formed from a rigid plastics material. The sheet may be formed by a single sheet and have two preparatory or incipient folds produced by pre-scoring or pre-grooving along the lines corresponding to the edges which are to be produced, the edges of the plastics sheet having notches at the extremities of each incipient fold. The invention also provides a method of and apparatus for manufacturing the box.