styling

I found the below in pdf-creator-lite/scripts/build-pdf-frontend.php. Maybe adding CSS to that would work. Try adding it before </style> in the last line.

//set some extra document css
$cssStr = ‘<style type=”text/css”> ‘;
$cssStr .= ‘.pageBreak { page-break-after: always; } ‘;
$cssStr .= ‘* { font-family:’ . $text_font . ‘; } ‘;
$cssStr .= ‘a { color:’ . $link_hex . ‘; } ‘;
$cssStr .= ‘a:visited { color:’ . $link_hex . ‘; } ‘;
$cssStr .= ‘ </style>’;

I needed something a little more user friendly so I made the plugin below then added:

$cssStr .= get_option('pdfcss');

Above:

$cssStr .= ' </style>';

My PDF Creator Lite CSS plugin:

<?php
/**
* Plugin Name: PDF Creator Lite Styler
* Description: Add custom CSS to PDF Creator Lite
* Version: 1.0
* Author: Sprogger
**/

add_action('admin_menu', 'pdfcsss');

function  pdfcsss() {
	add_submenu_page( 'tools.php', 'pdfcss', 'PDF Creator CSS', 'add_users','pdfcss_options', 'overview');
	add_action( 'admin_init', 'register_mysettings' ); //call register settings function
 }

function register_mysettings() {
	register_setting( 'myoption-group', 'pdfcss' );
 } 

function overview() { ?>

<div class="wrap">
<h2> Theme Option Panel</h2>
    <form method="post" action="options.php">
        <?php settings_fields( 'myoption-group' ); ?>
        <textarea name="pdfcss" size="80" value="<?php echo get_option('pdfcss'); ?>"><?php echo get_option('pdfcss'); ?></textarea>
        <p class="submit">
        <input type="submit" class="button-primary" value="<?php _e('Save Changes') ?>" />
        </p>
    </form>
</div>

<?php } 

?>

Ideally the PDF Creator Lite plugin would have a custom CSS window… but then I suppose it will no longer be lite!

@robindehaan Its a bit tricky but I was able to add an img tag to the top and bottom in pdf-creator-lite/scripts/build-pdf-admin.php and pdf-creator-lite/scripts/build-pdf-frontend.php
Original:

//build the page content
$htmlStr = '<h1>' . $title . '</h1>';
$htmlStr .= $PRcontent;

Modified:

//build the page content
$htmlStr = '<img src="http://placehold.it/350x150"><h1>' . $title . '</h1>';
$htmlStr .= $PRcontent;
$htmlStr .= '<img src="http://placehold.it/350x150">';