Sometimes when using TCPFD, you import a font via

$pdf->addTTFfont($allTheOptions);

and you end up with odd spaces between the single letters. But its not a space between the letters, as you can see. Its only one character on a much too bis space:

Error in Letterspacing

To correct that, you need to go to the font definition file which you should find in app/vendors/tcpdf/fonts and has a name like "arial.php". This is the TCPDF FONT FILE DESCRIPTION. Inside you will find the array $cw which starts like this:

$cw=array(0=>0,1=>750,2=>750,3=>750,4=>750,5=>750,6=>750,7=>750,8=>0

Now:

Mostly, that should do the trick immediately:

Correct Letterspacing in TCPDF