Remove paper size options on node add forms
Cross-posting my answer from drupal.org as these two pages are the first results in google.
https://www.drupal.org/project/print/issues/2714635


  I just fixed this on my works web site. The form alter code needs to be added in an #after_build callback as the paper size and orientation fields don't exist yet in the form array in using hook_form_alter. Here is a complete example.


/**
 * Implements hook_form_alter().
 */
function my_module_form_alter(&amp;$form, &amp;$form_state, $form_id) {

  // Hiding the print fields that print.module puts into the node form.
  if (strpos($form_id, '_node_form') !== FALSE) {
    $form['#after_build'][] = 'mhfa_pdf_form_alter_after_build_remove_print';
  }
}

/**
 * Remove pdf print controls.
 */
function my_module_form_alter_after_build_remove_print($form, &amp;$form_state) {
  unset($form['print']);
  return $form;
}