Will retrieve the registered paper sizes of PDF::API2.
print Dumper(\%sizes);
$VAR1={
'4a' => [ 4760 , 6716 ],
'2a' => [ 3368 , 4760 ],
'a0' => [ 2380 , 3368 ],
'a1' => [ 1684 , 2380 ],
'a2' => [ 1190 , 1684 ],
'a3' => [ 842 , 1190 ],
'a4' => [ 595 , 842 ],
'a5' => [ 421 , 595 ],
'a6' => [ 297 , 421 ],
'4b' => [ 5656 , 8000 ],
'2b' => [ 4000 , 5656 ],
'b0' => [ 2828 , 4000 ],
'b1' => [ 2000 , 2828 ],
'b2' => [ 1414 , 2000 ],
'b3' => [ 1000 , 1414 ],
'b4' => [ 707 , 1000 ],
'b5' => [ 500 , 707 ],
'b6' => [ 353 , 500 ],
'letter' => [ 612 , 792 ],
'broadsheet' => [ 1296 , 1584 ],
'ledger' => [ 1224 , 792 ],
'tabloid' => [ 792 , 1224 ],
'legal' => [ 612 , 1008 ],
'executive' => [ 522 , 756 ],
'36x36' => [ 2592 , 2592 ],
};