International Paper (the company profiled in this article) and most of the box manufacturers in the US use the software company I started, Lumi (YC W15)[0].
What is fascinating about these manufacturers is that many of them have been in business for more than 100 years and think on a multi-generational time scale. Managing forests and growing trees to turn them into boxes is a 25 year process.
There are a lot of old-timers working in these companies but I really enjoyed working with them. It's like we were the Hobbits interacting with Ents. They make decisions in a different way, and I found that refreshing. As a fast-moving startup it forced us to be aligned with their long term view of the world.