I would like to plot margins with multiple confidence intervals that appear as bars of narrowing thickness. Coefplot allows this by specifying something like "levels(99 95 90)". However, neither the margins nor marginsplot command is equipped to do this. I feel like I see these plots frequently, so there must be a way to make it happen. The best I can come up with is to make two rspike plots from margins and overlay them. Is there a better plan? Thanks for your advice.