diff --git a/sample_data/background.png b/sample_data/cards/background.png
similarity index 100%
rename from sample_data/background.png
rename to sample_data/cards/background.png
diff --git a/sample_data/cards/background_860px.png b/sample_data/cards/background_860px.png
new file mode 100644
index 0000000..f1b2908
Binary files /dev/null and b/sample_data/cards/background_860px.png differ
diff --git a/sample_data/cards/generate_card.sh b/sample_data/cards/generate_card.sh
new file mode 100755
index 0000000..aabb26d
--- /dev/null
+++ b/sample_data/cards/generate_card.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+mkdir -p output
+
+for img in input/*.{jpg,png}; do
+  [ -e "$img" ] || continue  # skip if no files
+  name=$(basename "${img%.*}").jpg
+  magick convert background.png \
+    \( "$img" -resize x820 \) \
+    -gravity center -composite \
+    -quality 85 -sampling-factor 4:4:4 \
+    "output/$name"
+done