Well, I have to say, "frankly, darling, it was a disaaaaaster!.
I punched a circle out with a nestie and stamped a doggie image onto it. Then added a little bit of colour with Sakura Gelly pens. The ink wasn't dry but I 'assumed' the heat from the heat gun would dry it. Well I can tell you, it doesn't! It ended up all smudged .....
So I cut out another circle and tag shape, stamped them up and left them to dry (thought it might take an hour or so but I had to leave them overnight before they were completely dry).
Shrunk them with the heat gun and this is the results ....
Frankly, they're rubbish and are no use for anything! but I'll probably have another go at some point. One thing I did learn is that the larger the piece of plastic you work the better the results seem to be i.e. the doggie circle has kept it's shape better than the smaller pieces.
Any tips gratefully received.