diff --git a/.Rbuildignore b/.Rbuildignore
index 0ff1239..b736d15 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -3,3 +3,4 @@
 ^LICENSE\.md$
 ^\.github$
 ^CODEOWNERS$
+^data-raw$
diff --git a/NEWS.md b/NEWS.md
index 9327a95..a75abf4 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,6 +1,7 @@
 # gex 0.2.0.9000
 
 * Added hex logo for the package.
+* Added 'resolution' argument to `open_device()`.
 
 # gex 0.2.0
 
diff --git a/R/hexagon.R b/R/hexagon.R
index 760f9e1..29a3d8c 100644
--- a/R/hexagon.R
+++ b/R/hexagon.R
@@ -6,6 +6,9 @@
 #'
 #' @param file_path Character. File path to a .png where the output file will be
 #'     saved. The containing directory must already exist.
+#' @param resolution Numeric. Resolution of the graphics device in pixels per
+#'     inch (ppi). Higher values have better resolution but create larger file
+#'     sizes.
 #'
 #' @details
 #'
@@ -31,7 +34,7 @@
 #' add_text()
 #' add_border()
 #' close_device()
-open_device <- function(file_path) {
+open_device <- function(file_path, resolution = 300) {
 
   if (tools::file_ext(file_path) != "png") {
     stop("Argument 'file_path' must end with '.png'.", call. = FALSE)
@@ -44,12 +47,16 @@ open_device <- function(file_path) {
     )
   }
 
+  if (!inherits(resolution, "numeric")) {
+    stop("Argument 'resolution' must be a numeric value.", call. = FALSE)
+  }
+
   grDevices::png(
     filename = file_path,
     width =  4.39,
     height = 5.08,
     units = "cm",
-    res = 1200,
+    res = resolution,
     bg = "transparent"
   )
 
diff --git a/README.md b/README.md
index b2b7aab..4b1076c 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# {gex} <a href="https://github.com/matt-dray/gex"><img src="man/figures/logo.png" align="right" height="139"/></a>
+# {gex} <a href='https://github.com/matt-dray/gex'><img src='man/figures/logo.png' align='right' width='200'/></a>
 
 <!-- badges: start -->
 [![Project Status: Active – The project has reached a stable, usable state and is being actively developed.](https://www.repostatus.org/badges/latest/active.svg)](https://www.repostatus.org/#active)
@@ -58,7 +58,10 @@ image_path <- system.file("img", "Rlogo.png", package = "png")
 image_png <- png::readPNG(image_path)
 
 # Build and write the hex
-gex::open_device(file_path = temp_path)
+gex::open_device(
+  file_path = temp_path,
+  resolution = 300  # ppi, you can increase this
+)
 gex::add_hex(col = "#BEBEBE")  # named or hexadecimal
 gex::add_image(
   img = image_png,
@@ -86,9 +89,9 @@ gex::add_border(col = "grey20")
 gex::close_device()  # writes to file
 ```
 
-That creates this absolutely stunning sticker, written to the specified `file_path`:
+That creates this absolutely stunning demo sticker, written to the specified `file_path`:
 
-<img src='man/figures/readme-hex.png' width='300' alt="A grey hexagon with a dark grey border. An R logo is shown just above centre and angled at 30 degrees. Just below centre is the text 'example' in monospace red and bold font. On the lower right edge is the URL 'htps://rstats.lol' in smaller, blue italic serif font.">
+<img src='man/figures/example.png' width='200' alt="A grey hexagon with a dark grey border. An R logo is shown just above centre and angled at 30 degrees. Just below centre is the text 'example' in monospace red and bold font. On the lower right edge is the URL 'htps://rstats.lol' in smaller, blue italic serif font.">
 
 Note that you can't rely on plot-window previews when you're developing your sticker (they lie).
 You must inspect the generated PNG file instead.
diff --git a/inst/tinytest/test_gex.R b/inst/tinytest/test_gex.R
index 6d8d55e..4c80b6b 100644
--- a/inst/tinytest/test_gex.R
+++ b/inst/tinytest/test_gex.R
@@ -9,7 +9,6 @@ dev_open <- open_device(temp_path)
 expect_null(dev_open)
 dev_close <- dev.off()
 expect_true(is.numeric(dev_close))
-unlink(temp_path)
 
 err_arg <- 'argument "file_path" is missing, with no default'
 expect_error(open_device(), err_arg)
@@ -22,6 +21,11 @@ expect_error(open_device("x/y.pdf"), err_png)
 err_dir <- "Argument 'file_path' must resolve to an existing directory\\."
 expect_error(open_device("x/y/z.png", err_dir))
 
+err_res <- "Argument 'resolution' must be a numeric value\\."
+expect_error(open_device(temp_path, resolution = "x"), err_res)
+
+unlink(temp_path)
+
 # Add hex -----------------------------------------------------------------
 
 hex <- add_hex()
diff --git a/man/figures/example.png b/man/figures/example.png
new file mode 100644
index 0000000..4bf47b1
Binary files /dev/null and b/man/figures/example.png differ
diff --git a/man/figures/logo.png b/man/figures/logo.png
index f416aa3..04055ef 100644
Binary files a/man/figures/logo.png and b/man/figures/logo.png differ
diff --git a/man/figures/readme-hex.png b/man/figures/readme-hex.png
deleted file mode 100644
index 61ed615..0000000
Binary files a/man/figures/readme-hex.png and /dev/null differ
diff --git a/man/open_device.Rd b/man/open_device.Rd
index 8db1321..47f1ad6 100644
--- a/man/open_device.Rd
+++ b/man/open_device.Rd
@@ -4,11 +4,15 @@
 \alias{open_device}
 \title{Open a PNG Device with Sticker-Standard Dimensions}
 \usage{
-open_device(file_path)
+open_device(file_path, resolution = 300)
 }
 \arguments{
 \item{file_path}{Character. File path to a .png where the output file will be
 saved. The containing directory must already exist.}
+
+\item{resolution}{Numeric. Resolution of the graphics device in pixels per
+inch (ppi). Higher values have better resolution but create larger file
+sizes.}
 }
 \value{
 Nothing. A graphics device is opened.