DeskJet 500C

The DeskJet 500C was HP's first 300 dpi colour printer. It was truly a marvel of chemistry, fluids and mechanics. Its only major drawback was that it produced a "process black" rather than a true black colour. The 500C shipped with only a single, tri-chamber colour cartridge (with cyan, magenta and yellow inks). To make the colour black, it mixed the three primary colours (which actually produced a grayish-greenish colour). But nevermind, other than the process balck, the colour output from the machine compared very well to other colour printers of the time costing ten times as much. The 500C was also fast. And, when users only needed to print black output, they could replace the colour cartridge with the standard black DeskJet cartridge and get near laser-quality output.