ChrisHurst

MyWebsiteAdvisor

This plugin allows you to Automatically add a watermark to all images as they are viewed on your WordPress Website. 
Watermarks are not permenant, original images are not edited. 
The plugin maintains a cached copy of the watermarked image, which can be cleared and regenerated at any time!
The plugin uses PNG watermark images with transparency for precise control over the appearance of the watermarks. 
This plugin also supports simple text watermarks with adjustable color, size and transparency. 
The user friendly settings page allows for control over the appearance of your watermark. 
The watermark preview feature allows for easy testing of the plugin settings. 
The watermark size is controlled as a percentage of the target image, 50% means the watermark will be half the width of the target image.
This plugin needs to add to your .htaccess file, and will not work if you do not have a .htaccess file or mod_rewrite.
NOTE: 
This plugin may have a slight impact on the performance of your web server, use of the Included Basic Caching System is Highly Recommended! 
The premium version of this plugin also includes an Advanced Cache System which performs nearly identical to when the plugin is disabled.
<a href="http://MyWebsiteAdvisor.com/tools/wordpress-plugins/simple-watermark/" rel="nofollow ugc">Upgrade to Simple Watermark Ultra</a> for advanced 
watermark features including:
<ul>
<li>Improved Performance with Advanced Cache</li>
<li>Fully Adjustable Image Watermark Position</li>
<li>Fully Adjustable Text Watermark Position</li>
<li>Adjustable JPEG Image Output Quality</li>
<li>Highest Quality Watermarks using Image Re-sampling rather than Re-sizing</li>
<li>Lifetime Priority Support and Update License</li>
</ul>
Developer Website: http://MyWebsiteAdvisor.com/
Plugin Support: http://MyWebsiteAdvisor.com/support/
Plugin Page: http://MyWebsiteAdvisor.com/tools/wordpress-plugins/simple-watermark/
Requirements:
<ul>
<li>PHP v5.0+</li>
<li>WordPress v3.3+</li>
<li>GD extension for PHP</li>
<li>FreeType extension for PHP</li>
<li>.htaccess file and mod_rewrite</li>
</ul>
To-do:

Simple Watermark

Automatically watermark images as they are viewed

Little Package

Canyon Webworks

PDF Ink Lite adds watermarks and password protection to every PDF your customers download from WooCommerce, Easy Digital Downloads, and Download Monitor. Watermarks can include customer-specific data like names, emails, and date, and are customizable with font face, font color, font size, vertical placement, and text.
PDF Ink Lite is the only free watermarker for WordPress which includes necessary libraries (so you don’t have to ask your host to load them), and watermarks newer versions of PDFs (not just older versions).
<h4>Features:</h4>
<ul>
<li>Choice of font face, color, size and placement (a horizontal line of text, centered anywhere on the page)</li>
<li>Included font types cover most languages, and the plugin is internationalized</li>
<li>Dynamic customer data inputs (customer first name, last name, email, order paid date, and phone) to customize PDFs on-the-fly</li>
<li>Add a password to your PDF, and/or anti-copy, anti-print protections</li>
<li>Watermark only designated PDF downloads (as specified by you), or all PDF downloads from your site</li>
<li>Watermark is applied to all pages of the PDF (<a href="https://pdfink.com/" title="Upgrade to the full version" rel="nofollow ugc">upgrade to choose pages</a>)</li>
<li>Accommodates different page/paper sizes, and PDFs with various page sizes (letter, A4, legal, etc)</li>
<li>Secure & encapsulated: PDF Ink hooks into e-commerce download link clicks and checks for PDFs and maybe marks them – that’s it!</li>
</ul>
For better PDF coverage and many more options, <a href="https://pdfink.com/" title="PDF Ink" rel="nofollow ugc">check out PDF Ink, the full version of PDF Ink Lite</a>.
<h4>Upgraded (paid) version features:</h4>
<ul>
<li>Clean, robust settings panels and a separate watermarking testing suite</li>
<li>Watermark all PDF files with same settings OR set individual watermarks/passwords per product or even per product variation</li>
<li>Begin watermark on selected page of PDF document (to avoid watermarking a cover page, for example), and/or select end page</li>
<li>Watermark every page, odd pages, even pages, or ranges of pages</li>
<li>Unlimited rotatable watermark locations on one page, anywhere on the page</li>
<li>Additional dynamic customer data input (business name, address, order number, product name, quantity of product purchased), and filter hooks for adding your own</li>
<li>Semi-opaque (transparent) watermarks – hide your watermarks completely if desired</li>
<li>RTL (right to left) watermarking</li>
<li>Use of some HTML tags to style your output, including text-align CSS styling (right, center, left is default), links (<a>), bold (), italic ()…</li>
<li>Additional text formatting options, such as font color and style (bold, italics) using HTML</li>
<li>Line-wrapping, forced breaks with and tags</li>
<li>Upload and use your own font for stamping. Also, hooks to further customize font use</li>
<li>Higher level PDF protections with AES encryption and extended file protection settings</li>
<li>Keep original and/or add file metadata</li>
<li>Edit or add PDF annotations, add embedded streams, and edit PDF outgoing (URI) links</li>
<li>Open ZIP files and mark PDF files inside the archive</li>
<li>Works with EPUB! Stamp EPUB files with customized text</li>
<li>Shortcode for creating PDF download links for any page (no need for e-commerce plugin)</li>
<li>Embed marked/encrypted files on the page, using ADOBE SDK embed or PDF Object JavaScript embed.</li>
<li>Test watermark and/or manually watermark a file on the fly, from the admin panel</li>
<li>Preserves external embedded PDF links despite watermarking; internal links (ToC) are not reliably preserved (<a href="https://pdfink.com/?source=wordpress" rel="nofollow ugc">add SetaPDF-Stamper to PDF Ink</a> for this feature)</li>
<li>Filter hooks to add 1D and 2D barcodes (including QR codes)</li>
<li>Remove stamped files from your server after stamping, or on a schedule</li>
</ul>
<a href="https://pdfink.com/" title="PDF Ink" rel="nofollow ugc">PDF Ink is priced below competitor plugins that offer maybe half the function.</a> Why? Because we want you to succeed! 🥰

PDF Ink Lite – Free PDF Watermark & Password Protection

Watermark and password protect PDFs with WooCommerce, EDD, and Download Monitor. No Ghostscript required, PHP 8+ compatible. Since 2014 (FKA WaterWoo)

Simple Watermark vs PDF Ink Lite – Free PDF Watermark & Password Protection