The most common and most likely answer to this crossword clue is the 11 letter word DILETTANTES
I've seen this crossword clue in The Daily Telegraph
D
I
L
E
T
T
A
N
T
E
S
More clues leading to the result DILETTANTES
Buddy explains!

The straight part
We know that "arty types" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case arty types = dilettantes.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DILETTANTES mean?
DILETTANTES noun- An amateur, someone who dabbles in a field out of casual interest rather than as a profession or serious interest.
- (sometimes offensive) A person with a general but superficial interest in any art or a branch of knowledge.