Question Author
Hi Smudge, I hope you'll come back and look at this thread, although it's over a week old.
I tried scraping the wording off, but wasn't successful - you could still see the imprint and it looked messy.
So I have cut the tree off the front of the cards, and made new cards with the trees. Good idea eh? I have lots of card-making materials, so I didn't have to go out and buy anything I haven't already got.
I've not done it to all the cards - I've sent a few as they are, with the wording on the back.
Thanks for your suggestion.