find a way to print with less ink

You can just use lighter colors. Rather than black, try 50% grey and see how well that works. Actually, I'd try printing a gradient from 100% black to 100% white, maybe 10 strips. One one side, make it a solid block of the grey. On the other side, print some text in that same shade. Let it dry for a day or two and see which parts are more likely to smudge.