Fig. 6. Individual droplets of three allowed sizes by the printer: small, medium and large. The horizontal spacing chosen was 250 μm. The droplets were printed on (a) normal print paper, (b) premium glossy photo paper, (c) a microscope glass slide and (d) a hydrophobic glass slide. The diameter of the smallest droplet on each substrate is (a) 70 μm, (b) 39 μm, (c) 57 μm and (d) 39 μm respectively. (e) Raster of medium sized single droplets with a programmed horizontal spacing of 250 μm and a vertical spacing of approximately 212 μm printed in the unidirectional mode, (f) the same raster printed in the bi-directional mode, (g) single droplets of small, medium and large size with the same horizontal spacing. A platen gap of 3.5 mm was used for all three situations. (h) The same print settings as previously described but with a platen gap of 6.8 mm.