My policy has always been for flat artwork and for other types of art such as fabric dolls, paper mache, jewelry, etc... that I there are no exchanges or returns. I always state that they should ask questions prior to bidding or purchasing. I'm more than willing to email the interested party larger more detailed photos, etc...
In over 30 years of doing business I've never had anyone question my policy. Nor, have I ever had anyone want to do an exchange or ask to return what they purchased.
Hope Everyone's 2017 Is Starting Out Well.
Funked Up Art