Like this simple example : 
Sample code :
<?php $string = "10€"; $font = "./arial.ttf"; // Adapted from http://www.phpbuilder.com/columns/cash20030526.php3?print_mode=1 // & // http://www.php.net/manual/fr/function.imagettftext.php header('Content-type: image/png'); // Image building $im = imagecreatetruecolor(70, 70); // Colors definitions $white = imagecolorallocate($im, 255, 255, 255); $yellow = imagecolorallocate($im, 255, 255, 0); $purple = imagecolorallocate($im, 89, 3, 255); //$grey = imagecolorallocate($im, 128, 128, 128); //$black = imagecolorallocate($im, 0, 0, 0); //$red = imagecolorallocate($im, 255, 22, 5); imagefilledrectangle($im, 0, 0, 70, 70, $white); function imagettftextoutline(&$im,$size,$angle,$x,$y,&$col, &$outlinecol,$fontfile,$text,$width) { // For every X pixel to the left and the right for ($xc=$x-abs($width);$xc<=$x+abs($width);$xc++) { // For every Y pixel to the top and the bottom for ($yc=$y-abs($width);$yc<=$y+abs($width);$yc++) { // Draw the text in the outline color $text1 = imagettftext($im,$size,$angle,$xc,$yc,$outlinecol,$fontfile,$text); } } // Draw the main text $text2 = imagettftext($im,$size,$angle,$x,$y,$col,$fontfile,$text); } imagettftextoutline( $im, // image location ( you should use a variable ) 20, // font size 0, // angle in ° 0, // x 25, // y $yellow, $purple, $font, $string, // pattern 2 // outline width ); imagepng($im); imagedestroy($im); ?>
