If you’re in a rush, the most important thing is to specify a paper that is 100% post-consumer waste (PCW) recycled. Often 100% PCW stocks will have other green attributes including being manufactured with renewable energy, processed chlorine free (PCF), Forest Stewardship Council (FCS) certification, and so on. Also, try to avoid the paper overseas or by rushed (airmail) delivery.
FYI
Cast Iron Design is now The Office of Ordinary Things. We relocated from Boulder to San Francisco, but otherwise we’re pretty much the same people doing the same things, just a bit more hardcore.