Abstract: A mosaic printer comprising a printing head with relative movability along a printing line on a printing sheet to be printed. The head supports a number of wire ends arranged along a substantially rectilinear line extending perpendicular to the printing line and each wire end upon excitation producing a printing mark on the printing sheet, desired signs being formed by selective activation of the said wire ends during relative motion of the printing head. According to the present invention at least the front portion of the printing head, which determines the orientation of the said substantially rectilinear line, is rotatable about an axis, which is substantially perpendicular to the printing sheet, whereby signs having different inclinations can be formed by rotating the front part of the printing head.