The ceiling tiles in donut shops were stained yellow, I can remember my husband showing me where a tile had shifted slightly so the portion that had been covered by the support frame was showing & it was so clean & white compared to the smoke stained area. I don't smoke but I'd go to a bar or a concert with squeaky clean hair & I'd get home & pass out. Even after changing my pillowcase & washing my hair the next day my pillow would still smell faintly of smoke.