Animal Crossing: New Horizons' Warm Painting is an item that can be donated to your island's museum or hung in your home. The Warm Painting is known as La Maga Vestida in real life, and it was created by the painter Francisco de Goya.
ACNH Warm Painting: Everything You Need to Know
Paintings play an essential role in finishing your museum collection. The hardest part of submitting artwork is discovering the differences between real and fake art on Redd's boat.
Redd is a sneaky fox that visits players' islands on random days, parking his ship at the back of the island. Players can purchase only one art piece a day.
After purchasing an art piece, it will be sent to your mailbox the next day. Unfortunately, players have to wait until Redd arrives back on their island in order to purchase another art piece.
Fortunately, Redd doesn't have a fake version of the Warm Painting, so players don't have to worry about zooming in and trying to spot any differences.
As for other paintings in the game, you can read more about how to tell if a painting is real here.
If you don't have an art gallery yet, you should mention building one to Blathers. After submitting 60 bugs, fossils, and fish to the museum, Isabelle will talk about Redd during her morning announcements.
You can then find Redd wandering around your island, who will introduce himself to you and try to sell a painting for 498,000 Bells, Luckily, Redd will eventually lower this price to 4,980 Bells.