A method is described for producing acyl glycinate salts of formula in which R1 represents a saturated linear or branched alkyl radical comprising 1 to 21 carbon atoms or a monounsaturated or polyunsaturated linear or branched alkenyl radical comprising 2 to 21 carbon atoms, and B represents a cation, andor the corresponding protonated acyl glycinic acid. Each wire supporting portion includes a servo motor with an axis of rotation, a magnet member around the axis of rotation, a bobbin having a conical surface around which wire is wound, and magnetically coupled to the axis of rotation by the magnet member, and a traversing mechanism for varying the position where the wire is wound around the length of the conical surface. When the plurality of data blocks are transmitted, the wireless communications device can initiate a block timer associated with a round trip time for communications between the wireless communications device and the receiving device. Return communications return data such as status and user interaction with the displayed information. Upon reception of this information, the PD printer makes image correction based on that image feature amount, and records an image.