I'm producing a pdf file using gl2ps, but the surface doesn't show up in the MacOSX previewer. (Lines and text are fine). The pdf file is available at http://www.stats.uwo.ca/faculty/murdoch/temp/persp3db.pdf . It looks fine in the Acrobat reader in Windows or on the Mac, but the surface doesn't show up in the default "Preview" pdf viewer on the Mac. Duncan Murdoch