Title font face ("plain", "italic", "bold", "bold.italic").
plot.title.space
Title spacing.
plot.title.position
Alignment of the plot title/subtitle and caption. The setting for plot.title.position applies to both the title and the subtitle. A value of "panel" (the default) means that titles and/or caption are aligned to the plot panels. A value of "plot" means that titles and/or caption are aligned to the entire plot (minus any space for margins and plot tag).
legend.position
the position of legends ("none", "left", "right",
"bottom", "top", or two-element numeric vector)
axis.title.space
Axis title spacing.
legend.title.size
Legend elements text size in pts.
legend.text.size
Legend elements text size in pts. Can be "none".
axis.title.size
Axis title text size in pts.
axis.title.face
Axis font face ("plain", "italic", "bold", "bold.italic").
axis.text.size
Axis text size in pts.
axis.text.angle
Rotate the x axis labels.
tags.size
Tags text size in pts.
tags.face
Tags font face ("plain", "italic", "bold", "bold.italic").