diff --git a/examples/lenna.png b/examples/lenna.png
new file mode 100644
index 0000000..59ef68a
Binary files /dev/null and b/examples/lenna.png differ
diff --git a/examples/mask.go b/examples/mask.go
new file mode 100644
index 0000000..fb6b195
--- /dev/null
+++ b/examples/mask.go
@@ -0,0 +1,20 @@
+package main
+
+import (
+	"log"
+
+	"github.com/fogleman/gg"
+)
+
+func main() {
+	im, err := gg.LoadImage("examples/lenna.png")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	dc := gg.NewContext(512, 512)
+	dc.DrawRoundedRectangle(0, 0, 512, 512, 64)
+	dc.Clip()
+	dc.DrawImage(im, 0, 0)
+	dc.SavePNG("out.png")
+}