The sheer number of different papers that Turner actually used differentiates him from many other artists. He acquired new papers on every journey on his constant travels throughout Britain and the Continent, either as whole sheets or as pages from sketchbooks.
It is highly likely that this paper came from one of the mills near Venice. Several of the ‘brown’ papers that Turner worked on in Venice are actually different tones of grey, mostly of Italian manufacture. Some have been badly affected by light damage, turning them from grey to various tones of dark brown.
Gallery label, September 2004