Thanks to everyone who helped earlier today. I am still working on multiple (4, exactly) contour plots of a data frame "nd.frame" with contourplot(): contourplot(zdf~xdf*ydf|factor(pndf),data=nd.frame) Everything is looking nice now, except I need to add a title to the color bar, or "key". It seems to me that this must be fairly elementary, but I have looked through three books and Google, and can't figure out how to do it. I have tried several things that produce either errors or nothing at all. Can anyone tell me how to add a title to the color bar of a set of contour plots? Thanks again! --Sam Cable