If I open the PDF file on that machine. Theres a margin around the outer edge that will vary depending on the printer. You could change to this be legal letter size. It would seem logical that an 812 x 11 page would print just fine on an 812 x 11 piece of paper. Im going to assume you mean slightly smaller. Very common scenario, before and after ever so slightly smaller to fit in printable area. T think you can get OO to embed the printer options in a document. However if the PDF is automatically sent to the printer after it is generated.
It detects the page size automatically and prints landscape. Then sends it to choose paper source by pdf page size mac the print queue on that. The problem is that most printers cannot actually print on the entire sheet of paper. However when passed to the printer through the application service it dees choose paper source by pdf page size mac not.
(And you can see a Zoom of 97 has been applied just under the preview.).PDF page size box.