Since <i>alla prima</i> painting has become the norm and we are consequently no longer conversant with the smallest details of the academic technique, the possibility that academic painters may have altered aspects of their technique to anticipate future changes in their materials has generally been overlooked. Although some 19th-century artists may have favored the touch of time which would mellow their work, according to most writers on British oil painting technique during the 19th century, future alterations were not welcomed. Rather, artists were offered practical advice on methods to circumvent changes such as ways to account for the yellowing of the medium or to allow for shifts in color from the fading or darkening of pigments.