I once did this with some stuff during reverse engineering, I printed about 20 portrait orientation A3 pages in colour of source code at the largest font size I

I once did this with some stuff during reverse engineering, I printed about 20 portrait orientation A3 pages in colour of source code at the largest font size I could without inducing any lines to wrap.... With that, some post it notes and a nice pencil I was able to spot the problem in the control flow I hadn't seen when moving around the source file on my computer screen. I'd be much more likely to buy this kind of thing in colour.