Inner and outer borders

Libraries

knitr::opts_chunk$set(collapse = TRUE)
library(flextable)
library(officer)

big_border = fp_border(color="red", width = 2)
small_border = fp_border(color="gray", width = 1)

ft <- flextable(head(airquality))
ft <- border_remove(x = ft)
ft <- border_outer(ft, part="all", border = big_border )
ft <- border_inner_h(ft, part="all", border = small_border )
ft <- border_inner_v(ft, part="all", border = small_border )
ft