Margins: Need more detail

I am using QuickPDF Library 7.23 on Delphi 7, XP.  I have a PDF file of a label that I need to print, programatically, without Adobe installed.    The label size is 3 inch wide by 1 inch high, and I'm using a Zebra LP 2844 to print the label.  I've created the label, with proper margins, in a different program specifically made for the purpose, and saved it as .Pdf.  When I open the file in Adobe, and print it, it prints perfectly.  However when I use QuickPDF, QuickPDF adds it's own margins (about 0.75 inch left and right, and about quarter inch top, zero bottom.  Using Quick PDF with the large margins, there's little room left in the center for the text on the label, so it word wraps.

I have read your other post about margins, where you tell about
http://www.quickpdflibrary.com/help/quickpdf/PageLayout.php and look at the SetPageDimensions and about layers and stuff.  This does me no good.  What are the parameter units in SetPageDimensions?  Inches?  Pixels?  Points?  Also, what functions, exactly, and how, should I use them to get rid of these unwanted margins?

Here is what I'm doing.. maybe you can tell me what I'm doing wrong:

Assume:      
...
qwk_pdf: TQuickPDF0723;
pdf_fnm: String;
...
    qwk_pdf := TQuickPDF0723.Create;
    if not UnlockedOK(qwk_pdf) then
...
  pdf_fnm := 'C:\_temp\my.pdf';
...


    qwk_pdf.LoadFromFile(pdf_fnm);
    qwk_pdf.PrintDocument(Printer.Printers[Printer.PrinterIndex], 1, 1, qwk_pdf.PrintOptions(0, 0, 'My Label'));

(Result:  Prints the label with a large three quarter inch left and right margin s and a one quarter inch top margin).

I know for a fact that the large left and right margins are not in the .Pdf file.  When I made the file, I set the margins to zero, and in Adobe, the margins are as I had created them.  QuickPDF is adding the margins on it's own.

Can you be more specific in your answer about margins, giving me a code snippet that includes the exact functions, with parameters that  I need to to this?  Thanks.  My project is stuck until I get an answer.