Fiddling with your browser print settings might work, but would mess up other print jobs unless you change them back. PITA.
Since eBay labels present as PDF files (which are a done deal with margins and layout baked in before your browser ever see them), unless eBay changes the layout, post processing of downloaded PDFs is the only path to a solution I see.
I download ALL my labels, and have for years. Allows for reprinting, archival, etc. I print PDF labels using PDF-XChange Viewer which has some powerful and useful features. For example, I have defined a few comment templates that I can apply for eBay, PayPal, Amazon, or USPS.com labels as needed. By defining comment fields that are essentially blank boxes, I can mask off parts of the label pages for printing (mask off receipt portion, print label, then move mask and print receipt on back off sales order, etc.)
PDF-XChange Viewer also has a crop feature that would solve your problem. Shift-Ctrl-T pulls up crop dialog, drag left margin in a bit, bottom margin up a bit, and apply. The Ctrl-P to print, and choose "auto centre pages in sheets". Because the left and bottom margins were trimmed, that pulls the label down and left.
I also use an Autohotkey macro for a standard PDF-XChange crop sequence I use most often that pulls up the crop dialog, applies margins I predefined, and closes the dialog when I hit Alt-Shift-Ctrl-I. That type of thing could automate setting margins for FedEx labels for you. (You would have to install Autohotkey but I can give you the script and help with modification to it if needed)
Might be possible to do something similar in Acrobat? (I haven't used Acrobat in a decade and don't think the old version on this machine is even intact any longer so not familiar with Acrobat usage and capabilities)
Another possibility is a drag and drop batch approach where command line utilities are used to modify the downloaded PDF label file and send it on to the default PDF print handler.
You would do your normal label print thing, but download the label as a PDF file (you would probably have to change your browser options to "ask every time" instead of just opening with Acrobat), then locate it on your system using Windows Explorer and either drag and drop it on a desktop shortcut to the batch routine, or alternatively, the batch routine can be set up as a right click context menu "Send to" target.
Here is a Windows batch file that uses an Autohotkey script to adjust downloaded eBay FedEx label PDF document margins. The amount of adjustment is controlled by the xoffset and yoffset environment vars set in the batch routine. Save the batch on desktop (or somewhere else and create a shortcut to it on the desktop to be able to drag and drop the PDFs onto it). Also need to adjust the location of the output file (tempofile) if desired.
@echo off
setlocal
::: Routine to adjust eBay FedEx label PDF margins for printing. Uses pdfmargins.ahk
::: Autohotkey script for the gruntwork. Currently only works for eBay FedEx labels
::: (eBay USPS labels are compressed and method produces corrupt unreadable result)
if not .%1==. if exist %1 goto doit
exit
:doit
::: Moving the PDF Mediabox here. Think of it as a viewport.
::: Use positive xoffset to move the MediaBox right which pulls the content left
::: and negative yoffset to move the MediaBox up which pulls the content down.
set xoffset=+30
set yoffset=-30
set tempofile=c:\pdftempfile.pdf
:::del any exisitng temp file
if exist %tempofile% del %tempofile%
:::call the compiled autohotkey script executable and pass it the parameters
pdfmargins.ahk.exe %1 %tempofile% %xoffset% %yoffset%
:::or alternatively call autohotkey to run the uncompiled script and pass it the parameters
:::"C:\Program Files\utils\AutoHotKey\AutoHotkey.exe" d:\pdfmargins.ahk %1 %tempofile% %xoffset% %yoffset%
if errorlevel 1 exit
:::open the fixed PDF with the default PDF handler
%tempofile%
:::or open the fixed PDF with a specific PDF handler and pass it parameters such as a print command
rem "C:\Program Files\PDF-XChange Viewer\PDF Viewer\PDFXCview.exe" /print:showui=no %tempofile%
rem pause
Now that batch is just a control interface for the PDFMargins.ahk Autohotkey script which is here:
;Autohotkey script to adjust PDF eBay FedEx Label margins berserkerplanet 12/13/18 v0.1
;Inputs: %1=PDF document filename %2=name of output file %3=xoffset %4=yoffset
;Offsets move the MediaBox (viewport) and are the opposite of the desired content move direction
FileRead, filebuffer, %1% ;Read PDF document into a buffer
;Find first MediaBox line in the PDF
foundpos:=RegExMatch(filebuffer,"m)/MediaBox\s*\[(\d{1,4})\s*(\d{1,4})\s*(\d{1,4})\s*(\d{1,4})\]",pattarr)
if(foundpos=0)
exit 1
Soundbeep 300,10
;Grab the existing Mediabox coodinates and adjust them with the passed offsets
y0=%pattarr1%
y0+=%4%
x0=%pattarr2%
x0+=%3%
y1=%pattarr3%
y1+=%4%
x1=%pattarr4%
x1+=%3%
newmargins=/MediaBox [%y0% %x0% %y1% %x1%] ;Construct a new MediaBox line
StringReplace, newPDF, filebuffer, %pattarr%, %newmargins%, All ;Replace the MediaBox line
FileAppend, %newPDF%, %2% ;Write the changed PDF to the passed temp file name
exit 0
Either obtain and install Autohotkey to run that script or use the version I compiled to a standalone executable which is available here: https://berserkerplanet.altervista.org/code/scripts/pdfmargins.ahk.exe (about 200kb)
Easiest thing is to drop it in c:\windows since that is on the path by default - otherwise you need to put it somewhere on the windows path, or put it somewhere else, and adjust the call to it in the batch file to point to it's specific location.
Once that is done, you just download your eBay FedEx label, and drag n drop it on the desktop batch file shortcut. It will pass that PDF filename along with a name for a temp output file and the x and y margin offsets to the compiled script, which will scrounge through the PDF, adjust the MediaBox line in the PDF, write the modified version to the temp output file, and try to invoke your default PDF handler to then print the adjusted label.
Actually works quite well. Only works for eBay FedEx labels a this point as the are uncompressed PDFs and can be edited with a text editor (or modified by the text method used by the script). USPS labels are compressed PDF's, and even when I decompressed a couple of them using other tools, the modifications cause corruption of the resulting output that made those copies of the labels unreadable. May look into that later.
BTW, you can make the same margin changes to the eBay FedEx label PDF with Notepad or another TEXT editor. Around line 147 in the PDF change /MediaBox [0 0 792 612] to /MediaBox [-30 30 762 642] open it in Acrobat or whatever PDF viewer, and print it. (Amount of adjustment can be tweaked to suit)
