I'm currently trying to use Arial.ttf in all my plots. I have found several manuals about fonts online, I'm however running into issues when I try to save the pot via ggsave and the default device.

Minimal working example

I'm running the following minimal working example to reproduce this bug:

Sys.setenv(R_GSCMD="D:/gs/bin/gswin64c.exe")

library(ggplot2)

require(extrafont)
font_import(prompt = F, pattern = "arial.ttf")
font_import(prompt = F, pattern = "JOKERMAN.TTF")
loadfonts(device="win", quiet = T)
loadfonts(device="pdf", quiet = T)

plot <- ggplot(mtcars, aes(wt, mpg, colour = hp)) + geom_point()
jokerman_plot <- plot + theme_bw(base_family = "Jokerman")
arial_plot <- plot + theme_bw(base_family = "Arial")

ggsave("arial_plot.png", arial_plot)
ggsave("arial_plot.pdf", arial_plot)
embed_fonts("arial_plot.pdf")

ggsave("jokerman_plot.png", jokerman_plot)
ggsave("jokerman_plot.pdf", jokerman_plot)
embed_fonts("jokerman_plot.pdf")

This results in the following (correct) PNG images:

The Arial PDF, however, has all characters stacked on top of each other (the Jokerman PDF renders correct):

Warning output

The following warning messages are generated by this script.

Warning messages:
1: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x68
2: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x70
3: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font metrics unknown for character 0x4d
4: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x68
5: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x70
6: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x4e
7: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x41
8: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font metrics unknown for character 0x4d
9: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x31
10: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
11: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
12: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x31
13: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x35
14: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
15: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x32
16: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
17: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
18: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x32
19: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x35
20: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
21: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x33
22: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
23: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
24: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x4e
25: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x41
26: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x4e
27: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x41
28: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x31
29: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
30: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
31: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x31
32: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x35
33: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
34: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x32
35: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
36: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
37: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x32
38: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x35
39: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
40: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x33
41: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
42: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x30
43: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x4e
44: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x41
45: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x6d
46: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x70
47: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x67
48: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font metrics unknown for character 0x4d
49: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x6d
50: In grid.Call(L_textBounds, as.graphicsAnnot(x$label),  ... :
  font width unknown for character 0x70

Session info

My current sessionInfo()

R version 3.3.0 (2016-05-03)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)

locale:
[1] LC_COLLATE=German_Germany.1252  LC_CTYPE=German_Germany.1252    LC_MONETARY=German_Germany.1252
[4] LC_NUMERIC=C                    LC_TIME=German_Germany.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] extrafont_0.17      ggplot2_2.1.0       RevoUtilsMath_3.2.5

loaded via a namespace (and not attached):
 [1] labeling_0.3     colorspace_1.2-6 scales_0.4.0     assertthat_0.1   plyr_1.8.3       tools_3.3.0     
 [7] gtable_0.2.0     ggthemes_3.0.3   Rcpp_0.12.5      extrafontdb_1.0  grid_3.3.0       digest_0.6.9    
[13] Rttf2pt1_1.3.4   munsell_0.4.3

Attempted solutions

I've tried several ways of renaming the generated AMF files to no avail
I've thought that maybe the encoding of my source file might matter, so I changed it to UTF-8 (no change)
Resetting extrafontdb multiple times
Reinstalling ghostscript multiple times

Workarounds

I have currently two workarounds, I would, however, prefer to use the "native" PDF device as configured in R or ggplot for portability sake

Specify cairo_pdf as a device (This can cause secondary issues with output or some plots to render slightly different). The PDF is fine, so could this point to a bug in the default PDF device?
Use PNG/bitmap output (I want to use the plots in print, so vector output is preferred)
Rely on R using ArialMT as default. I'm not sure if ArialMT is exactly the same font as used in my (Latex) document, so I would like to specify to font explicitly.