Scribus claims to be able to convert RGB/CMYK colors to spot colors: http://documentation.scribus.net/index.php/Spot_Colors
I've never used Scribus, but it's floss. Jeremy
______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.