Think I'm going to need to give this a bit more thought. I can see what you're saying and that it would be handy for customers to have an easy way to return stuff if it's not right/damaged. But if we're sending out, say, 50 orders a day we'll need to calculate carriage ad hoc for every order as reverse collections aren't a standard cost for us, along with printing etc.. most of which will have no comeback, so probably will be a big waste of time and money for us.
Downloading and printing a label is a better idea in my opinion, I'm just in this morning and heading out shortly to take some videos of the Rotapump doing thin coat renders today. When I next get a chance, I'll get in touch with Fedex and see if they have any arrangements that wouldn't make it cost an arm and a leg.
If anyone has any other ideas let us know!