A method of forming a sealed wrapping about an article, the method comprising the steps of: folding a sheet of wrapping material about the article, so the folded sheet has a pair of facing, substantially parallel, projecting flaps (19, 19'); superimposing and sealing the pair of flaps (19, 19') to form a substantially tubular partial wrapping having two open ends, and a first sealing flap projecting outwards crosswise to the partial wrapping; folding the first sealing flap onto an outer surface of the partial wrapping; successively gripping and sealing the open ends of the partial wrapping; deforming at least one of the open ends of the partial wrapping by means of a retractor, to form two facing flaps; and gripping and sealing the facing flaps to form a respective closed end portion and a second sealing flap, which projects from the end portion and defines a seal of the end portion; folding the second sealing flap onto the end portion so that two tabs of the second sealing flap project laterally from the end portion and on opposite sides of the end portion; and folding each tab onto the end portion; wherein the sheet of wrapping material is folded and sealed about the article so that the partial wrapping comprises two major lateral portions on opposite sides of the article; and two minor lateral portions which are located on opposite sides of the article, are crosswise to the major lateral portions, and are connected to the major lateral portions by respective lateral edges; the first sealing flap extending substantially along a respective lateral edge, and being folded onto one of the major lateral portions of the partial wrapping; and the open ends of the partial wrapping being closed and sealed by gripping them to form the two second sealing flaps substantially crosswise to the first sealing flap and to the minor lateral portions; wherein the tabs are folded onto the end portion as the sheet, folded about the article, is fed in a direction substantially parallel to said end portion and to said tabs, and in particular crosswise to the major lateral portions. folding a sheet of wrapping material about the article, so the folded sheet has a pair of facing, substantially parallel, projecting flaps (19, 19'); superimposing and sealing the pair of flaps (19, 19') to form a substantially tubular partial wrapping having two open ends, and a first sealing flap projecting outwards crosswise to the partial wrapping; folding the first sealing flap onto an outer surface of the partial wrapping; successively gripping and sealing the open ends of the partial wrapping; deforming at least one of the open ends of the partial wrapping by means of a retractor, to form two facing flaps; and gripping and sealing the facing flaps to form a respective closed end portion and a second sealing flap, which projects from the end portion and defines a seal of the end portion; folding the second sealing flap onto the end portion so that two tabs of the second sealing flap project laterally from the end portion and on opposite sides of the end portion; and folding each tab onto the end portion; wherein the sheet of wrapping material is folded and sealed about the article so that the partial wrapping comprises two major lateral portions on opposite sides of the article; and two minor lateral portions which are located on opposite sides of the article, are crosswise to the major lateral portions, and are connected to the major lateral portions by respective lateral edges; the first sealing flap extending substantially along a respective lateral edge, and being folded onto one of the major lateral portions of the partial wrapping; and the open ends of the partial wrapping being closed and sealed by gripping them to form the two second sealing flaps substantially crosswise to the first sealing flap and to the minor lateral portions; wherein the tabs are folded onto the end portion as the sheet, folded about the article, is fed in a direction substantially parallel to said end portion and to said tabs, and in particular crosswise to the major lateral portions.