Custom html.tpl.php from module for custom type
Modules can use hook_preprocess_html() to override theme templates. You need 3 things: 


A hook_preprocess_html() implementation
A hook_theme() implementation
A html template in your module dir 


Using a module called MYMODULE, with a new node type mynodetype, &amp; a template in the module dir named templates/html--mynodetype.tpl.php, we can add the following hooks to MYMODULE.

/**
 * Implements hook_preprocess_html().
 */
function MYMODULE_preprocess_html(&amp;$vars) {
  $node = menu_get_object();

  // Add a new theme suggestion when viewing node's of mynodetype.
  if ($node &amp;&amp; $node-&gt;nid &amp;&amp; $node-&gt;type == 'mynodetype') {
    $vars['theme_hook_suggestions'][] = 'html__mynodetype';
  }
}

/**
 * Implements hook_theme().
 */
function MYMODULE_theme($existing, $type, $theme, $path) {
  $theme = array();

  //Add our templates/html--mynodetype.tpl.php to the theme registry
  $theme['html__mynodetype'] = array(
    'template' =&gt; 'html--mynodetype',
    'path' =&gt; drupal_get_path('module', 'MYMODULE') . '/templates',
  );
  return $theme;
}