This ink, unlike most fountain pen inks, behaves well enough for writing two-sided on bad paper, rarely even "shadowing" through. I like the blue color, too (darker than both Parker and Pelikan/Cross blues). It is washable, so parents can give it to kids without worrying. It is also erasable/eradicable by sulfate-sulfite eradicators like the Pelikan Super Pirat, which is convenient for students. This ink is from the factory in Slovenia. It is free-flowing and almost pH-neutral, so it is safe for any pen and any paper.