Complex sentence: He left clues of the paintings' true nature for fellow art restorers or conservators to find; for instance, he might write revealing text onto the canvas with lead white before he began to paint; x-rays would then reveal the text.
Split into simpler sentences: He left clues of the paintings' true nature for fellow art restorers or conservators to find. For instance, he might write text onto the canvas with lead white before he began to paint; x-rays would then reveal the text.