If you need to create a PDF using Tcpdf that isn’t a standard size (A4, A5, B1, LETTER etc.) then it is possible to specify a custom size even though it isn’t that well documented. To do this you need to pass an array containing the desired width and the height of the PDF instead a formatted parameter such as ‘A4′. For example:

// create new PDF document
$pdf = new TCPDF(PDF_PAGE_ORIENTATION, PDF_UNIT, PDF_PAGE_FORMAT, true, 'UTF-8', false);
 
// add a page
$resolution= array(100, 100);
$pdf->AddPage('P', $resolution);

Make sure you express the height and width in the unit of measurement (pt, px, mm, cm etc.) that you are using as well.