Hi @arthrnvrn,
The easiest way to achieve it is using the {{product_custom_field::META_KEY}} placeholder, within the Product item column block in the customizer, included in Premium Templates:

However, if you have some PHP knowledge, you can take advantage of the PDF template action hooks and write a code snippet to achieve it.
Here’s an example as reference:
add_action( 'wpo_wcpdf_after_item_meta', function( $template_type, $item, $order ) {
if ( isset( $item['product'] ) && ! empty( $your_custom_field = $item['product']->get_meta( 'your_custom_field' ) ) ) {
echo '<div class="custom-field">Your Custom field: '.$your_custom_field.'</div>';
}
}, 10, 3 );
Great, thank you @yordansoares !
And, any idea how to make metas inline (sku/weight) ?
Try adding this code snippet to your site to achieve it:
/**
* WooCommerce PDF Invoices & Packing Slips:
* Makes SKU and Weight metadata inline
*/
add_action( 'wpo_wcpdf_custom_styles', function( $document_type, $document ) {
if ( $document_type == 'invoice' ) {
?>
dt.sku, dt.weight, dd.sku, dd.weight {
display: inline-block;
}
dt.weight:before {
content: "|";
margin-right: 2pt;
}
<?php
}
}, 10, 2 );