Abstract: Reinforced single-face corrugated fiberboard containers of remarkable strength are disclosed which can be mass produced at minimum cost in a high-speed continuous process from a continuous sheet of single-face corrugated material comprising a corrugated web adhesively secured to a single facing sheet having a width much greater than that of the web to provide outwardly extending fly portions of substantial width. The web forms the corrugated core of a single-wall laminated board formed by turning over the fly portions to reinforce the side edges and adhesively securing the fly portions to the corrugations to partially cover the core and to provide the board with double-faced side portions and an unreinforced single-faced middle portion.