Many thanks to Patrick Connolly and Deepayan Sarkar for their quick responses to my query. In essence, grid graphics cannot be used in conjunction with base R graphic functions such as mtext(). Deepayan suggests using bold() in the ylab in place of font = 2; the bold() does produce the desired font in ylab.
Richard ______________________________________________ [EMAIL PROTECTED] mailing list http://www.stat.math.ethz.ch/mailman/listinfo/r-help
