Silly question that may not have a definitive answer:

What is the general rule (APA 6 would be even nicer) for matching a graphic's (say a scatterplot) font to the main body of the font.

I often make my graphics (when I say often I eman always) in R and my paper/article body is times new roman (in following apa 6 style). The default R font is not times new roman. It looks good though and I think times new may not look as good.

Discussion? Thoughts? Rules?