The phrase "art true" can be interpreted in different ways, but it suggests authenticity, accuracy, and sincerity. Antonyms for this phrase would include words that connote the opposite of those qualities. For example, "artifice" implies deceit or trickery, while "deception" suggests an intention to mislead. "Falsehood" and "fiction" both denote something that is not factual or truthful. "Inaccuracy" implies a lack of precision or correctness, while "insincerity" suggests a lack of genuineness or honesty. All of these antonyms suggest a departure from the qualities of authenticity, accuracy, and sincerity that are associated with the phrase "art true.