Attractive item in painting finally captured by French painter (6)
I believe the answer is:
magnet
'attractive item' is the definition.
(I've seen this in another clue)
'painting finally captured by french painter' is the wordplay.
'finally' suggests the final letters.
'captured by' indicates putting letters inside.
'french painter' becomes 'manet' (I've seen this in another clue).
The final letter of 'painting' is 'g'.
'g' placed into 'manet' is 'MAGNET'.
'in' acts as a link.
(Other definitions for magnet that I've seen before include "Attractive piece of metal" , "Powerful attractor" , "Lodestone, for example" , "Attractor of iron" , "what's attractive" .)