I need help - I can help - Bates Stamping Question

Does anyone know if there is an 'official' way to bates stamp (serialize individual pdf pages with a numeric (and possibly a prefix or suffix))?

I am trying to bates stamp some already-existing PDF documents with multiple pages.

I was able to do this using the DrawText function in Quick PDF Library (function written for powerbasic is shown below).

The problem I am having is that my program doesn't erase bates stamping on pages created by third party programs. My experience is, from using a few third party bates stamping programs, is that stamping with one program erases the bates stamp added with another, so they all seem to be adding serialized page numbers using the same technique and that appears to be something different than using drawtext.

Here is the function I am using, in case someone needs to add something that looks like bates stamping. I did have to fiddle a bit with the location (note where I had to add 150 to the page height) to get the text to draw in the lower right hand corner of the page. It would be good to understand why that extra + 150 was needed.

Thanks in advance.

Ken

FUNCTION AddPageNumberPDF() AS LONG
'http://www.quickpdf.org/forum/add-page-numbers-to-existing-pdf_topic2096.htm
LOCAL myid AS LONG, i AS LONG
LOCAL ph,pw AS DOUBLE

dplLoadFromFile( gLibInstance1&,"sample1_bates.pdf","")
myid = dplAddStandardFont( glibinstance1&,4)

FOR i = 1 TO dplpagecount(gLibInstance1&)

'https://www.debenu.com/docs/pdf_library_reference/SelectedPage.php
  dplSelectPage( gLibInstance1&,i)

'https://www.debenu.com/docs/pdf_library_reference/NormalizePage.php
  dplNormalizePage( gLibInstance1&,0)

'https://www.debenu.com/docs/pdf_library_reference/SetOrigin.php
  dplSetOrigin(gLibInstance1&,1)  'Specifies which page corner to use for the origin: 0 = Bottom left (default), 1 = Top left, 2 = Top right, 3 = Bottom right, Anything else = Bottom left

'https://www.debenu.com/docs/pdf_library_reference/Fonts.php
'https://www.debenu.com/docs/pdf_library_reference/Text.php

'DPLFontType(int InstanceID)  'https://www.debenu.com/docs/pdf_library_reference/FontType.php

'selectfont: Select one of the fonts which have been added to the selected document. The FontID must be a valid ID as returned by one of the Add*Font functions or returned by GetFontID .

 dplSelectFont(gLibInstance1&,myid)

'https://www.debenu.com/docs/pdf_library_reference/SetTextSize.php
 dplSetTextSize(gLibInstance1&,12) 'Set the size of the text to use for any subsequently drawn text. The text size is always measured in points, even if the measurement units have been changed with SetMeasurementUnits.
 dplSetTextColor(gLibInstance1&,1,0,0)   'sets text color to red.   NOTE : Each color component has a range of 0.0 to 1.0   and not 0 to 255 like many other libraries.

 ph = dplPageWidth(gLibInstance1&)
 pw = dplPageHeight(gLibInstance1&)

'for some reason I had to use 70% of pw to get correct width and + 150 to get correct vertical location on bottom of page (else was too high or too far to right to be visible)
  dplDrawText( gLibInstance1&,pw *.70 ,ph + 150,"pg1 " & FORMAT$(i)) 'pw - 30, ph - 20, "Page" +  format$(i))
NEXT i

dplSaveToFile( gLibInstance1&,"newfile.pdf")
END FUNCTION