change thickness of the whole line geom_boxplot()

Question

I would like to increase the boldness of the entire boxplot to be more visible on the hard copy. from Here seems "fatten" parameter change the thickness of the only median line. Is there any other parameter that control the thickness/width of the the whole box plot ?

require(reshape)
require(ggplot2)
cars_melt = melt(cars)

ggplot(aes(x = variable, y = value), data = cars_melt) + 
  geom_boxplot(fatten = 2) 

Answer 1

Use geom_boxplot(lwd=3) ("lwd" for "line width"). Also, if lwd makes the median too thick, you can use lwd and fatten together to make the median line thinner relative to the other lines.