Display UTF-8 string with your PDFlib and true type font
<?php
$pdf = pdf_new();
if (!pdf_open_file($pdf, ""))
exit;
PDF_begin_page($pdf, 600,800);
pdf_set_parameter($pdf, "textformat", "utf8");
$fontdir = "/path/to/font/directory/";
pdf_set_parameter($pdf, "FontOutline", "ArialUnicode=$fontdir/ARIALUNI.TTF");
pdf_set_parameter($pdf, "FontOutline", "ArialItalic=$fontdir/ariali.ttf");
$utf_8_string ="Потребление" ;
$font = PDF_findfont($pdf, "ArialUnicode", "unicode",0);
pdf_setfont($pdf, $font, 15);
pdf_show_xy($pdf, "Arial Unicode : $utf_8_string" ,40 ,700);
$font = PDF_findfont($pdf, "ArialItalic", "unicode",0);
pdf_setfont($pdf, $font, 15);
pdf_show_xy($pdf, "Arial Italic : $utf_8_string" ,40 ,650);
PDF_end_page($pdf);
pdf_close($pdf);
$buf = pdf_get_buffer($pdf);
$len = strlen($buf);
header("Content-type: application/pdf");
header("Content-Length: $len");
header("Content-Disposition: inline; filename=foo.pdf");
echo $buf;
pdf_delete($pdf);
?>