Although all German and foreign catalogues list the varieties of the 1870 20c. blue of France in three types, still few are seen in collections, probably on account of the difficulty heretofore felt in explaining the differences.
The cuts I., II., and III. illustrate exactly the differences of the Greek ornaments at the lower light side of the frame (compare with Figure IV.).
Even in the very poorly printed specimens these varieties in the lines of the Greek ornaments are prominent, and in the very heavy impressions where the shadings of the main lines are invisible, the distinguishing points are still plain.
TYPE I.
TYPE II.
TYPE III.
It will be simple for everybody to now distinguish these types with the aid of the illustrations. In addition the main points will be easy to memorize.