[R] plotting to postscript: how to control line width ?

[ryszard.czerminski@pharma.novartis.com]

How to control line width ?

if I do:

> postscript("IC50-density.eps", width = 4.0, height = 3.0, horizontal = 
FALSE, onefile = FALSE, paper = "special", title = "IC50 distribution")
> plot(d$x, d$y, xlab = "-log10(IC50)", ylab = "density")
> lines(d$x, d$y, lwd = 0.1)
> dev.off()

but whatever value I give for ldw parameter (e.g. 0.1 or 10) I am getting 
the same line width ?!