I believe every printer driver, at least the ones I have tried, "knows" the minimum border edges for that particular printer. And the numbers are not necessarily identical, left, right, top, or bottom. Every printer can be different.
One way I have figured out how to find out what the minimums are is to use Word.
First set for your desired printer (in case you have more than one printer)
then set up one Word page with 0" margins (top, bottom, left, and right).
Then when you press the [OK] you will be warned that "one or more margins are set outside the printable area of the page".
You should then take the [Fix] selection.
Once you get that page adjusted just look at the page margins to find out what those minimums are.
Write that down somewhere, as a reference.
If you have other printers, do the same again, starting with 0" margins.
There's your minimums.
When i setup USER DEFINED paper in MS Word, and try to print with HP, then MS Word pops a flag saying "margins of section 1 are set outside printable area of page!"
MS Word prevents me from sending USER DEFINED paper size to HP printer.
It wants me to use only Default Paper Sizes before use L/R margings to move HP print head to where i want it to print! But that require too much calculations, try-error, and waste of ink! Does all HP printers do that?
When i send the same USER DEFINED paper setup to Epson, it doesn't pop any "margings" flag! It sends the the same margins to Epson to print exactly where i want it but refuses to do it for HP.
How do i setup CUSTOM PAPER sizes in MS word for HP printer?
PLEASE NOTE: that changing USER DEFINED paper size from HP's own printer properties can't overide MS word setup. The margin flag still pops! and it makes HP print outside specified area
NOTE ALSO that because WordPad does not have setup PAPER SIZE under USER DEFINED paper, it allows HP to use its own USER DEFINED paper sizes to print excatly where i want it.
That explains the problem is surely between MS Word and HP
How do i setup CUSTOM PAPER sizes in MS word for HP printer?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic