Leonardo da Vinci Study of woman's head ca. 1485-90 drawing on blue paper Royal Collection, Windsor Paper tinted blue (by papermakers, during manufacture) was a moderately fashionable commodity in Renaissance Europe, in demand for writing, drawing, and even letterpress printing. This blue-paper fashion expanded and peaked during the 18th century. Samples chosen here are fairly well-preserved, though less vivid than they once were. Many such papers have faded to gray or to some indeterminate…