Thank you Zak and Haddock for the methods of holding the tea leaves down.
Have used watered down PVA and as you can see from the photo have left a test bit undone - its larger than I was going to leave but run out of PVA so that's the reason.
If the PVA does not hold the leaves firm enough will try Haddocks method of a coat of varnish on top.
We live and learn -- that's what I like about this club, nobody holds onto bits of information or skills, they are happy to help others improve -- and yes I do need a lot of improving before you say it.