--- image_captcha/image_captcha.admin.inc.orig	2008-03-26 15:07:22.000000000 +0100
+++ image_captcha/image_captcha.admin.inc	2008-03-26 15:09:31.000000000 +0100
@@ -86,6 +86,14 @@
       '1.5' => t('large'),
     ),
   );
+  // font fine tuning
+  $form['image_captcha_font_settings']['image_captcha_font_space_tuning'] = array(
+    '#type' => 'textfield',
+    '#title' => t('Fine tuning'),
+    '#description' => t('Some fonts may require adjusting this parameter to prevent cutting off at the edges.'),
+    '#default_value' => variable_get('image_captcha_font_space_tuning', '0'),
+    '#size' => 4,
+  );
 
   // distortion and noise settings
   $form['image_captcha_distortion_and_noise'] = array(
--- image_captcha/image_captcha.user.inc.orig	2008-03-26 15:07:13.000000000 +0100
+++ image_captcha/image_captcha.user.inc	2008-03-26 15:09:06.000000000 +0100
@@ -56,10 +56,11 @@
   // get other settings
   $font_size = (int) variable_get('image_captcha_font_size', 30);
   $character_spacing = (float) variable_get('image_captcha_character_spacing', '1.2');
+  $space_tuning = (float) variable_get('image_captcha_font_space_tuning', '0');
   $characters = _image_captcha_utf8_split($code);
   $character_quantity = count($characters);
-  $width = $character_spacing * $font_size * $character_quantity;
-  $height = 2 * $font_size;
+  $width = $font_size * ( $character_spacing * $character_quantity + 2 * $space_tuning );
+  $height = $font_size * ( 2 + $space_tuning);
 
   // create image resource
   $image = imagecreatetruecolor($width, $height);