How to Add Watermarks in PDF Reports in Odoo 18: Complete Guide

Odoo 18 introduces advanced integrated watermarking capabilities into its PDF reporting engine, providing greater control of business documents. With this update, enterprises can strengthen brand identity and improve document security without having to use third-party tools.

Technical System Architecture

The upgraded QWeb template system provides several ways to configure watermarks, ranging from settings applied to a single report to options that affect every document produced across the company. It also supports condition-based watermarks that adjust according to the document's status, such as showing "Draft", "Cancelled", or custom brand elements when required.

Thanks to CSS styling and XML inheritance, developers can minutely define how each watermark is shaped, placed, blended, and rotated. The improved QWeb templating engine allows multiple levels of watermark application, from custom settings for specific reports to global rules that apply to all documents generated.

Business Benefits of Watermarking

Method 1: Text-Based Watermarks

The core method for adding text-style watermarks in Odoo 18 reports uses a positioned div element with CSS styling:

<div class="watermark-text" t-if="report_type == 'pdf'"
     style="position: absolute;
            transform: translate(0%, -170%) rotate(-45deg);
            -webkit-transform: translate(0%, -170%) rotate(-45deg);
            color: coral;
            font-size: 6em;
            opacity: 0.15;
            pointer-events: none;
            z-index: 0;">
    CONFIDENTIAL
</div>

Key CSS Properties Explained

Method 2: Image-Based Watermarks

With Odoo 18 reports, you can include image-based watermarks that enable embedding company logos or custom graphics into generated PDFs:

<div class="watermark-img" t-if="report_type == 'pdf'">
    <img src="/your_module/static/src/img/watermark.png"
         style="position: absolute;
                top: 25%;
                left: 15%;
                width: 70%;
                opacity: 0.1;
                pointer-events: none;
                z-index: 0;"/>
</div>

Complete Example: Sales Order Watermark

Here's a complete example of how to add a "CONFIDENTIAL" watermark to every page of the generated sale order PDF:

<?xml version="1.0" encoding="UTF-8"?>
<odoo>
    <!-- Custom Watermark Template for Sale Order Reports -->
    <template id="custom_sale_order_watermark" 
              inherit_id="sale.report_saleorder_document">
        <xpath expr="//div[@class='page']" position="inside">
            <!-- WATERMARK TEXT -->
            <div class="watermark-text" t-if="report_type == 'pdf'"
                 style="position: absolute;
                        transform: translate(0%, -170%) rotate(-45deg);
                        -webkit-transform: translate(0%, -170%) rotate(-45deg);
                        color: coral;
                        font-size: 6em;
                        opacity: 0.15;
                        pointer-events: none;
                        z-index: 0;">
                CONFIDENTIAL
            </div>
        </xpath>
    </template>
</odoo>

Conclusion

Adding watermark features in Odoo 18 PDF reports provides a powerful combination for document protection and reinforces branding. Whether it's a label like "CONFIDENTIAL" for sensitive documents or your company's logo for branding consistency, these approaches help deter unauthorized sharing while keeping a professional and polished look on all your business documents.