When printing non-color text on paper, you generally want to print the text as dark as possible, for maximum contrast.
With this new “two-sided mirror printing” idea, text can be printed darker than is normally possible, with this one trick: the printer automatically prints a mirror image of your text on the opposite side of the page.
This mirror-image text contributes (very slightly) to darkening the overall text on the side that is intended to be read (Figure 1).
This process has been empirically tested: it actually does work, but is only really noticeable if you hold the paper up to a light. See Figures 2 and 3 for experimental evidence.
Although this method uses twice as much ink (and potentially twice as much paper), it produces text that is subtly higher contrast under very specific lighting conditions.
The brightness measuring technique shown in Figure 3 is methodologically questionable; I don’t recommend plagiarizing it in your Methods section if you are attempting to publish a research paper.
PROS: Increases text contrast, helps support the struggling printer supply industry, which has been hit hard by the diabolical “Paperless Office.”
CONS: May increase unsustainable usage of natural resources, hastening the transformation of the Earth into a barren and windswept wasteland, devoid of all life and completely silent except for the sound of printers attempting to automatically clear a paper jam.