He painted it, twice going round article (6)
I believe the answer is:
titian
'he painted' is the definition.
(16th-century painter)
'it twice going round article' is the wordplay.
'twice' becomes 'it' (I can't justify this - if you can you should give a lot more credence to this answer).
'going round' says the letters should be written backwards.
'article' becomes 'an' (indefinite article).
'it'+'it'='itit'
'itit' reversed gives 'titi'.
'titi'+'an'='TITIAN'
Can you help me to learn more?
(Other definitions for titian that I've seen before include "Colour named after artist" , "It. painter, famous for redheads" , "Painter, noted for works with bright auburn hair" , "Italian painter of the Venetian school, patronised by Philip II of Spain" , "The painter Tiziano Vecellio" .)