Pertaining to, or having an interest in, the arts - often pretentiously and affectedly so.
This UK term refers to the sort of artistic work or interest that the Bonzo Dog Band's Vivian Stanshall called "Art with a capital F". It began to be used in the 1960s, whilst the variant preferred in the USA, 'artsy-fartsy', is recorded from the early 1970s.
The use of the vulgar 'farty' as the reduplicated variant of 'arty' works well in puncturing the pomposity of the affectedly artistic types who are mocked by this term.
See other reduplicated phrases.