A hanging image floats like any other, but part of it has been pulled out of the column. The lines still shorten — this is a float, and that is what floats do — but they give up only the part of the picture still standing inside the measure.

That is the trade this arrangement exists to make. Inside a forty-rem column a picture wide enough to be worth looking at leaves the text too narrow to read; hanging a third of it in the margin buys the width back without shrinking the picture.

How far it hangs is not a fixed distance but whatever room the band leaves around the column, up to a ceiling. That is why this specimen hangs a little here and further on the full page — the same arrangement, given more margin to use.