Painting fine Scilly isle, but not the capital (6)
I believe the answer is:
'painting' is the definition.
(I know that fresco is a type of painting)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for fresco that I've seen before include "Painting done in wet plaster" , "Mural painting" , "Forces (anag) - wall painting" , "Artistic work" , "Mural painted on wet plaster" .)