From South 12th:

Ruling pens are amazing devices, and I still have one somewhere that I use for ink drawings on occassion. It works a little like a dip pen, where pressure draws the ink up into that cavity, and you use the knob to adjust the width. With enough practice, you can make incredibly fine, straight, continuous lines with ink that would be impossible with even a quill tip or dip pen.

Another proponent of the ruling pen: Chris Ware — although I’ve seen multiple interviews with him bemoaning the lost hours spent learning such an archaic and obsolete device. From Chris Ware, a biography by Daniel Raeburn:

I do all the curves with a brush, I do all straight lines with a ruling pen. I try to get my pictures to read like words, so that when you see them you can’t make yourself not read them, in the same way that when you see a printed word you can’t make yourself not read it, no matter how hard you try.

Clearly that hard work didn’t pay off at all.

(image: “Untitled,” Quimby the Mouse letterpress print by Chris Ware)