I tried it with fltk, same result, with qt no plane at all. I would
like to print it with the print command, since there are many options,
size etc. Any ideas?
To create transparency, I use the gnuplot backend with gnuplot version 4
and I print to an svg file which I then convert to pdf using Inkscape.
Maybe there are easier paths nowaday, this was the only reasonably
working one that I found two years ago, and it still works in one of my
scripts.
graphics_toolkit ("gnuplot");
gnuplot_binary("gnuplot4");
print([fname ".svg"]);
system(["inkscape --export-pdf=" fname ".pdf " fname ".svg], [], 'async');