Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Useless Duplex Printing

The duplex printing feature is useless because in duplex mode the printer mixes color inks to create black rather than using the black tank. This wastes an incredible amount of expensive ink and produces lousy, washed-out black.Tech support claims that this is because the black ink would show through to the other side of the paper, whereas the lousy washed-out black may not. I haven't yet tried a paper in which this was the case (I reverted to the old-fashioned method of printing odd/even pages and flipping them around) and am convinced that it's really just an underhanded ink-selling strategy.