Drupal does not indicate variable $base_url in print.tpl.php. file. Even if it is (re)commented in settings.php file.

Even if it is (re)commented in settings.php file. So when creating custom template for printout if image path with be for example /sites/all/themes/tendu/logo.png"> image wouldn’t be displayed.
solution
To add <?php global $base_url; ?> to the beginning of the template

It is possible to set per-content-type and/or theme-specific templates which are searched for in the following order:

1. print_[format].node-[type].tpl.php in the theme directory
2. print_[format].node-[type].tpl.php in the module directory
3. print_[format].tpl.php in the theme directory
4. print_[format].tpl.php in the module directory
5. print.node-[type].tpl.php in the theme directory
6. print.node-[type].tpl.php in the module directory
7. print.tpl.php in the theme directory
8. print.tpl.php in the module directory (supplied by the module)

format is either html, mail or pdf, and type is Drupal's node type (e.g. page, story, etc.)
It’s fare for any global variable. These variables are not passed to template. For being short you can write
<?php
print $_GLOBALS["base_url"]
?>