Abstract: A printing mechanism comprises a housing, providing a print head carrying a flat type face, and a platen for supporting a forwardly moving sheet that is interposed between the platen and the type face. The platen includes an extended planar portion adjacent the sheet and movable parallel with it. Means are provided for bodily rotating the print head relative to the housing around an axis that is substantially parallel to the plane of the sheet, and in a path lying in a plane that is substantially perpendicular to the plane of the sheet so as to bring the type face into printing contact with the sheet against the platen planar portion; the planar portion is moved parallel with the sheet and at the same linear speed during the printing contact.