gnuplot - adjust size of key/legend

Question

How do I adjust the size of the legend in gnuplot (4.6.0)? By this I mean the size of the lines and not just the font size. When I switched from the pdf to pdfcairo terminal the size suddenly jumped and caused the key to overlap the points of interest. (I needed cairo to enable unicode.)

An answer I have just invented is (e.g.):

set key font ",8"
set key spacing 0.5

Is there a better way?

Answer 1

To adjust the length of the samples:

set key samplen X

(default is 4)

To adjust the vertical spacing of the samples:

set key spacing X

(default is 1.25)

and (for completeness), to adjust the fontsize:

set key font "<face>,<size>"

(default depends on the terminal)

And of course, all these can be combined into one line:

set key samplen 2 spacing .5 font ",8"

Note that you can also change the position of the key using set key at <position> or any one of the pre-defined positions (which I'll just defer to help key at this point)