Spec work is doing any kind of unpaid creative work with the hope of winning a client or contenst. Unfortunately doing unpaid work hurts everyone in our industry, especially those from marginalized demographics. If you are curious why we and most of our respected colleagues avoid this type of work you can read more about the issue on Spec Work or read AIGA’s Official Stance on the matter.
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.