Complex sentence: Another artist, Tony Johansen, took legal action against the Art Gallery of NSW Trust over the portrait arguing that because Ruddy predominantly used charcoal in his work, it was a drawing, not a painting, and therefore was ineligible for the prize.
Split into simpler sentences: Another artist, Tony Johansen, took legal action against the Art Gallery of NSW Trust over the portrait. Johansen argued that because Ruddy predominantly used charcoal in his work, it was a drawing, not a painting, and therefore was ineligible for the prize.