in reply to Print HTML-documents just once

The only way this can be done is having the user download a compiled program that securely connects to your server, gets the data to print the labels and doesn't allow printing of multiple copies. Because of this you can't do it through the normal Windows printing routines.

Even then it would not be too difficult to install a default printer which "prints" the label to a PDF-file and thus allows this file to be printed many times.

CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law