I have a colour Plotter, Why do my mono line drawings have a green or purple tint to them?
In Modern Inkjet printers,The Black ink is a high contrast Pigment, for pure black, and the colours tend to be a mixable dye. This is why modern printers can produce so many colours. if there is a problem with the black printhead, the print firmware tries to create a composite black from the other colours. In Designjet 500 / 800 series printers this comes out as a green / dark brown. In other Designjets it comes out as a dark blue/purple. When this happens the first thing to do is to Clean the black printhead. simply take a lint free cloth moisten with warm bottled or deionised water (or a PC wipe impregnated with IPA) and wipe the printhead till clean. On older Designjets you may also have to prime the printhead using the plunger assembly. If this doesnt work, then the problem is that the black lines intersect other colours and the composite black HAS to be used.It isnt normally noticeable in Colour line drawings, as its only the intersection that is composite. But in Graphic Applicat
