Grid line width seems to be equal to axis line width.
Though in gnuplot the grid lines half-tone which makes it kind of
bearable.
For 3-d plot gnuplot lost half of the axes and vertical grid lines in
X=0 and Y=0 planes (though this is probably an older problem).
Also the axis width in 3-d plots does not change with 'DefaultAxesLinewidth'
parameter (OK in qt/fltk).
Anyway
set(0, 'DefaultAxesLinewidth', 5)
plot(randn(3))
grid on
sombrero
with all 3 backends.
Currently I see it on changeset: 22112:03764eef9f7c, but I saw it a few revs
earlier as well.
Dmitri.
--