Gavin I know how you feel its happened to me. You but your first clear coat on you stand back and it looks great , you apply another coat and it looks even better. Then slowly you notice a small mark on your art work , you say shit whats this and before your eyes it starts growing like a virus , your heart misses a few beats then you fell like hitting it with a axe this will fix it. 
It seams to happen when the top coat is applied too thick in some areas. Because this is happened to me in the past I stick to the mylar.
You are spot on Mark - its the first time this has happened to me though and on previous CC's i didnt even go in light for first coat....never an issue before.. i had complete confidence in what i was doing.
To be quite honest - i was never that happy with the paints anyway - they take far too long to set, recently in wet weather, i had to wait 3 days for it to cure.
Ive been to my local paint supplier and bugged the crap out of him matching my Pantone inks to Tint range acrylic lacquer, plus a few extra tints for good measure... 4 ltrs of acrylic clear and some inhibitor.
Having walked away from the PF and then gone back - it looks worse than it is. Ive sanded down one side. The pink is now smooth but the lettering remains intact. This will be redone in the acrylics and CC will be acrylic also..alas though, not in time for Expo... instead ill be taking 2 other PF's with me.
63wizz,
The pink was applied months ago - last colour to go on was minor touch ups on the red - this was unaffected
