A high-speed phase change ink image producing machine having a phase
change ink delivery system including particulate pastille solid phase
change ink for enabling the high-speed phase change ink image producing
machine to produce images at a rate exceeding 50 prints per minute, the
particulate pastille solid phase change ink consisting essentially of (i)
sub-granular size particulate pastilles for heating and melting into
liquid phase change ink, (ii) each sub-granular size particulate pastille
is waxy and melts at less than about 120.degree. C., and (iii) each
sub-granular size particulate pastille has a size of one of very fine
sand, fine sand, medium sand and coarse sand having a diameter of less
than 1 mm on the Wentworth-Udden particle-sizing scale