Re: dashed line

> or do you have an idea of another trick?

what you could do:
plot curve 1 solid, curve 2 solid, curve 1 dashed line

an example:

set xrange [-pi:pi]
set yrange [-1.1:1.1]
set term post col dash
set style line 1 lt 1 lc 2 lw 5
set style line 2 lt 3 lc 2 lw 5
set style line 3 lt 1 lc 1 lw 5
set out 'plot.ps'
plot sin(x) ls 1, 1.02*sin(x) ls 3, sin(x) not ls 2
set out