Customize Commerce Event Ticket PDF content
You can customize the PDF content by using the HOOK function &lt;YourCustomModule&gt;_commerce_event_ticket_pdf_alter($pdf, $ticket, $context) or for simpler manipulation use &lt;YourCustomModule&gt;_commerce_preprocess_commerce_event_ticket_pdf_info(&amp;$variables).

Take a look at:
https://www.drupal.org/node/2407879 and https://www.drupal.org/node/2269659

It's also possible to replace the theme function by altering the theme registry:

function &lt;YourCustomModule&gt;_commerce_theme_registry_alter(&amp;$theme_registry) {
  if (!empty($theme_registry['commerce_event_ticket_pdf_info']['function'])) {
    $theme_registry['commerce_event_ticket_pdf_info']['function'] = '&lt;YourCustomModule&gt;_commerce_commerce_event_ticket_pdf_info'; // Your function to alter the content...
}


You should also have a look at the repository on GitHub -> gausie/commerce_event_ticket