For an article I'm working on, I thought I'd redo my old illustrations.
1. A gas of hadrons, with mesons (quark and antiquark) and baryons (three quarks or three antiquarks). Each cluster is contained by its own "bag":
2. A quark-gluon plasma, with the same quarks, but with "bags" disappeared and gluons flying around in their place.
All the rest is commentary. Any questions? And yes, I really did try and get the gluons right (sigh).