Physics textbooks as pillows for when you fall asleep at your desk, ranked:
Top Tier: these could essentially replace actual pillows. Soft, yet supportive, you can fall comfortably asleep regardless of what page you’re open to. Paper softness and thickness taken into account.
Second tier: Not bad, but you won’t wake up well rested. These ones mostly lose points for being oddly proportioned, just a little less support than I would like, or oddly hard paper.