A liquid jetting apparatus of the invention includes a head having a nozzle, a pressure-changing unit for causing pressure of liquid in the nozzle to change in such a manner that the liquid is jetted from the nozzle, and a jetting-mode setting unit for setting a selected jetting mode from a plurality of jetting modes. The track groove is divided into a plurality of blocks. The polymer solution may then be combined with an aqueous dispersion of pigment andor release agent which dispersions may include an aqueous polyelectrolyte andor an aqueous dispersion of colloidal particles. When the blade is mounted on the adaptor, the central hole of the blade mounts on the corresponding one of a plurality of differently sized radial support surfaces on the adaptor so that the axis of rotation of the blade is substantially co-axial with that of the spindle. The elastomeric member may be supported by a reinforcing member.