How to show free products only in PDF Catalog for WooCommerce

This requires customisation to the core plugin and your changes will be replaced next time the plugin is updated so beware that you will need to re-apply.

  1. Find and edit the file pdfcatalog2/classes/PDFCatalogGenerator.php
  2. Search forĀ $loop = new \WP_Query($args);
  3. Paste the following code right before that line:
    $args['meta_query'][] = array(
           'key' => '_price',
           'value' => '',
           'compare' => '='
       );
  4. Save the file and delete any cached catalogs from the Cache tab in the plugin’s settings.
  5. Refresh the catalog and only products without any price will show up.