Try creating same methods which you want to override from AbstractPdf.php in your overided Invoice.php file. For example, if you want to change the font:

1. Create a preference for Invoice.php in di.xml

<preference for="Magento\Sales\Model\Order\Pdf\Invoice" type="Vendor\Module\Model\Order\Pdf\Invoice" />

2. In Vendor\Module\Model\Order\Pdf\Invoice, create a function _setFontRegular

   /**

   • Set font as regular
   • @param \Zend_Pdf_Page $object
   • @param int $size
   • @return \Zend_Pdf_Resource_Font */ protected function _setFontRegular($object, $size = 7) { $font = \Zend_Pdf_Font::fontWithPath( $this->getFontsDir() . ('your-font-name') ); $object->setFont($font, $size); return $font; }

Try creating same methods which you want to override from AbstractPdf.php in your overided Invoice.php file. For example:

1. Create a preference for Invoice.php in di.xml

<preference for="Magento\Sales\Model\Order\Pdf\Invoice" type="Vendor\Module\Model\Order\Pdf\Invoice" />

2. In Vendor\Module\Model\Order\Pdf\Invoice, in you case create a method insertOrder

   /**

   • Insert order to pdf page
   • @param \Zend_Pdf_Page &$page
   • @param \Magento\Sales\Model\Order $obj
   • @param bool $putOrderId
   • @return void
   • @SuppressWarnings(PHPMD.CyclomaticComplexity)
   • @SuppressWarnings(PHPMD.NPathComplexity)
   • @SuppressWarnings(PHPMD.ExcessiveMethodLength) */ protected function insertOrder(&$page, $obj, $putOrderId = true) { // comment relevent code according to your requirement }