[ADD] Prioritize background transparency

report_qweb_pdf_watermark/README.rst

@@ -21,6 +21,10 @@ To use this module, you need to:
     :alt: Try me on Runbot
     :target: https://runbot.odoo-community.org/runbot/143/8.0
 
+Known Issues
+============
+This module depends on support for transparent backgrounds in Wkhtmltopdf, which has been flaky in the past. This module has been reported to work with Wkhtmltopdf 0.12.4.
+
 Bug Tracker
 ===========
 

report_qweb_pdf_watermark/__manifest__.py

@@ -14,5 +14,6 @@
     "data": [
         "demo/report.xml",
         "views/ir_actions_report_xml.xml",
+        "views/layout_templates.xml",
     ],
 }

report_qweb_pdf_watermark/static/src/css/report_qweb_pdf_watermark.css

@@ -0,0 +1,3 @@
+body {
+    background: transparent !important;
+}

report_qweb_pdf_watermark/views/layout_templates.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<odoo>
+    <!-- Include fix for https://github.com/odoo/odoo/issues/16610 -->
+    <template id="assets_pdf" inherit_id="report.assets_pdf">
+        <link position="after">
+            <link href="/report_qweb_pdf_watermark/static/src/css/report_qweb_pdf_watermark.css"
+                  rel="stylesheet"/>
+        </link>
+    </template>
+</odoo>