HP Latex 2700 User Guide 3 - Page 293

● Uniform variations from tile to tile. When color changes uniformly it must be within the color consistency specification; see Color consistency on page 41 for more details. Usually grays are much more sensitive: differences of less than 2 dE 2000 may be visible, although other colors would not show a difference. ● Small color variation left to right. The tile itself looks uniform, but when putting it beside the adjacent tile the differences become visible. ● Local color variations. See Local color variations on page 282. Sometimes these defects become visible only when printing tiles, showing in one of the tiles but not in the adjacent. They are also more visible when printing grays. ● Try to ensure uniform printing of all tiles, and all tiles printed in the same run. ● Rotate every other tile, to compensate for left to right differences. ● Adding spit bars at both sides of the image helps overall, especially when there are local color variations. Edge roughness, text quality The edges of objects may appear rough or blurred; this is especially noticeable in text. There are five possible causes: ● Bleed: see Bleed, halo, wicking on page 284. ● Printhead alignment. As ink could be deposited by a combination of different colored printheads, it is important that all printheads are correctly aligned. To do so, print the printhead-alignment verification plot (see Manual alignment procedure on page 127), and correct any misalignment. ● Substrate advance. Before trying to adjust any parameter, make the following checks: - Check that no substrate-advance factor was set earlier that could prevent the substrate-advance sensor from working correctly. - Run the diagnostics to check that the substrate-advance sensor is not dirty. 286 Chapter 14 Troubleshoot print-quality issues