title: Laravel Excel paper size setup
body: <p>I'm using Maatwebsite/Laravel-Excel package to generate some payment bills.
  I generate the excel and then export it to pdf (vía ->download('pdf') method) so the user can download it and print it without any hassle.
  This may not be the most elegant way, but I found this way pretty straightforward and easy to implement.
  I need to generate the pdf in half letter paper size to match the paper sheets that have been pre-printed with logos and stuff in specific positions.</p>
  
  <p>I can't find in the docs how to change paper size or pdf exporting options.
  Thank you.</p>