The most common and most likely answer to this crossword clue is the 8 letter word WHISTLER
I've seen this crossword clue in Independent
W
H
I
S
T
L
E
R
More clues leading to the result WHISTLER
- Artist you would get a peep out of?
- American painter who uses wind instrument?
- Artist who sounds cheerful
- Painter with seconds to stop megalomaniac
- Flyer ultimately heartless gets in with fascist leader
- Mountain road parts as long as river
- Bird painter
- Make shrill sound meeting Regina or Rex?
- Artist sees women slither about
- Canadian resort artist
Buddy explains!

The straight part
We know that "Painter" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case painter = whistler.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 WHISTLER mean?
WHISTLER noun- Someone or something that whistles, or who plays a whistle as a musical instrument.
- Any of several passerine birds of the genus Pachycephala, of Australasia and the western Pacific.
- Any bird that whistles or is noted for its whistling vocalisations (applied regionally to various specific species).
- The goldeneye (certain ducks of genus Bucephala).
- The whistling marmot (Marmota caligata).
- The mountain beaver (Aplodontia rufa).
- An audio-frequency electromagnetic wave produced by atmospheric disturbances such as lightning.
- A broken-winded horse.
- The keeper of a whistling shop, or shebeen.