Since WordPress 3.3 wp_print_styles
should not be used to enqueue styles or scripts. (see: http://make.wordpress.org/core/2011/12/12/use-wp_enqueue_scripts-not-wp_print_styles-to-enqueue-scripts-and-styles-for-the-frontend/)
Use wp_enqueue_scripts
instead.
wp_print_styles() is located in wp-includes/functions.wp-styles.php
wp_enqueue_scripts
- for enqueuing on the front endlogin_enqueue_scripts
- for enqueuing on the login pageadmin_enqueue_scripts
- for enqueuing on admin pagesEnqueue Styles
Enqueue Scripts
Front-End Hooks
Admin Hooks
Login Hooks