Gnuplot pngcairo arial-bold font Pango-WARNING

Question

I'm using Gnuplot 4.6 in Windows with the pngcairo terminal to plot some stuff. If I try to use the arial-bold font I get the following error:

Pango-WARNING **: couldn't load font "arial-bold, Not-Rotated 360", falling back to "Sans Not-Rotated 360", expect ugly output.

This is the same without the -, and when I use a specified size (adding ,x). It's weird because I never specify this 'Not-Rotated' business, and when I only use arial and arial,x it isn't mentioned (and the script runs smoothly). Is there another font I could use, or some other way to tell it to make the font bold?

This is the main part of my script (omitting line style definitions and other touchups):

set output "./Paired CDFvsdRd Graph #17.png
set title "Effect of IRSS LWIR @ 10m (15kts, φ=all°)" offset 0,1 font 'arial-bold,30'
set term pngcairo dashed size 1280,960
set key font "arial,14"
set xlabel "dRd [AU]" offset 0,-1 font "arial-bold,18"
set ylabel "CDF" offset -1,0 font "arial-bold,18"
set mxtics 5 ; set mytics 5
set grid xtics mxtics ytics mytics ls 6, ls 5
set xrange [-0.612187:0.421873]       # Change [min:max] to desired x range

plot './Paired CDFvsdRd Graph #17.csv' u 1:2 title "IRSS, 15kts, θ=30°" w l ls 1,\
'./Paired CDFvsdRd Graph #17.csv' u 5:6 title "IRSS + HFC, 15kts, θ=30°" w l ls 2,\
'./Paired CDFvsdRd Graph #17.csv' u 9:10 title "IRSS, 15kts, no-sun" w l ls 3

I'm using Gnuplot 4.6 patchlevel 5

Answer 1

Ok, so apparently there is a significant-enough difference between arial-bold and Arial-Bold. That was all -.- It's weird, because I was sure that I had started off with using capital font names and eventually after seeing many examples online of people using lower-case names and trial-and-error testing for an hour I stopped bothering capitalizing.