Who often writes multipage letters knows the problem: three A4 pages in the envelope are the maximum for the standard letter. If you choose, however this paper, you can save just 1/3 weight and can thus send four sides. This saves on the time postage costs. The only downer: the inkjet printer should print on one side of the paper because the font else shines through. With a laser printer that's not a problem because not feeding into the paper in laser printers dye, provided that the printer supports double-sided printing at all, otherwise dirty you look at the fixing drum.
