Question: [This example](https://tcpdf.org/examples/example_028/) on tcpdf's website shows how to use page formats like A4, A5 etc, but how do I set tcpdf to use custom sizes like 175mm x 266 mm?

Solutions appreciated.

Answer: 
Go to /config/tcpdf\_config.php and around line 117, modify the line:

```
define ('PDF_PAGE_FORMAT', 'A4');

```

by

```
define ('PDF_PAGE_FORMAT', 'LETTER');

```

It is important to put "LETTER" in uppercase, you can see all possible values in this file: `tcpdf/include/tcpdf_static.php`.
The truth, now you can solve it like this.

```
//AddPage [P(PORTRAIT),L(LANDSCAPE)],FORMAT(A4-A5-ETC)

$pdf->AddPage('P','A5');

```

Source:
<https://tcpdf.org/examples/example_028/>