I\'d like to create a figure using ggplot2\'s facet_grid, like below:
# Load ggplot2 librar
Of course, I find a solution immediately after asking. The problem appears to be that tag_facet sets strip labels to element_blank, which can be fixed by calling theme after calling tag_facet.
# Load libraries
library(ggplot2)
library(egg)
#> Warning: package 'egg' was built under R version 3.5.3
#> Loading required package: gridExtra
# Create plot
p <- ggplot(mtcars, aes(mpg, wt))
p <- p + geom_point()
p <- p + facet_grid(gear ~ cyl)
p <- tag_facet(p)
p <- p + theme(strip.text = element_text())
print(p)

Created on 2019-05-09 by the reprex package (v0.2.1)