The message
from Grunff contains these words:

someone on BBC business lunch today asked, what happens if your printer
screws up and tears up the envelope. They say there's a fix for this.


You put a new envelope in and print it again?

Seems reasonable. After all, the whole point of using unique barcodes is
so you can't reproduce them fraudulently. Printing it again should be
easy.

--
Skipweasel
Pay no attention to that man behind the curtain.