Solution for ISO-8859-* encoding

Here is a solution for BALTIC (or any other) character encoding. 

1. [url=http://www.fpdf.org/makefont/]http://www.fpdf.org/makefont/[/url] use this link to generate 2 files from .ttf font file and choose your encoding. I used arial font and 'ISO-8859-4' encoding.

2. Upload these two generated files to ext/fpdf/font/ folder. 

3. in classes/pdf.inc change line 9 and 14

$txt = mb_convert_encoding($txt, 'Windows-1252', language::$selected['charset']);
to this:
$txt = mb_convert_encoding($txt, 'ISO-8859-4', language::$selected['charset']);

4. In modules/order/om_pdf_invoice.inc.php

add line:
$pdf->AddFont('ariel','','arial.php');
below:

      $pdf->SetMargins(10, 2, 10);
      $pdf->SetAutoPageBreak(true, 2);```
and change all lines similar
```$pdf->SetFont('Arial', 'B', 10);```
to use new font generated:
```$pdf->SetFont('ariel', '', 10);```
Thats it.