documentation fix, horizontal to vertical
diff --git a/user_guide/libraries/image_lib.html b/user_guide/libraries/image_lib.html
index 59e2667..49da433 100644
--- a/user_guide/libraries/image_lib.html
+++ b/user_guide/libraries/image_lib.html
@@ -532,7 +532,7 @@
<td class="td"><strong>wm_vrt_offset</strong></td>
<td class="td">None</td>
<td class="td">None</td>
-<td class="td">You may specify a horizontal offset (in pixels) to apply to the watermark position. The offset normally moves the watermark to the right, except if you have your alignment set to "right" then your offset value will move the watermark toward the left of the image.</td>
+<td class="td">You may specify a vertical offset (in pixels) to apply to the watermark position. The offset normally moves the watermark to the right, except if you have your alignment set to "right" then your offset value will move the watermark toward the left of the image.</td>
</tr>
<tr>