Thanks for the comments Dave.
I will have a look at your suggestions. One thing I did notice was that if I pulled the key initially without using the Keylight Despill the key is actually quite good and the talent looks ok but as I have mentioned it goers wrong when using the built in Despill, however, if I use a separate Despill plugin I don’t seem top get the aforementioned grain after applying?
In relation to the green BG being to hot what kind of levels do the green BG need to be for future reference, thanks