Introducing the Penny Red
1841 Twopenny Blue, trial colors, November 20, 1840
1841 Twopenny Blue, chosen trial color AA, November 1840
1841 Twopenny Blue, specimens sent to Rowland Hill by Perkins, Bacon, October 26, 1840
1841 Twopenny Blues, January 1841, Post Office specimens
Plate 3, 1841 Twopenny Blue, imprimatur impressions, February 25, 1841
Plate 4, 1841 Twopenny Blue, imprimatur impression, December 6, 1849