Complex sentence: Fumiani was responsible for painting what is claimed to the largest painting on canvas in the world consisting of 60 separate canvases, it covers the whole of the ceiling of the church Chiesa di San Pantaleone Martire, known as San Pantalon, in Venice.
Split into simpler sentences: Fumiani was responsible for painting what is claimed to the largest painting on canvas in the world. It covers the whole of the ceiling of the church Chiesa di San Pantaleone Martire, known as San Pantalon, in Venice.