Charles, the way I do it is I print international labels on 8.5x11
paper, fold that in half, put it in the pouch, and I've never had a
problem that way before. Only hassle is changing the ShipStation
setting.
ShipStation, you are so close already. I created an automation rule that
is halfway there. Criteria: "Country is not equal to United States." The
"Add an action" button should have an option for "set default printer to
[insert printer]"
