One example is a souvenir sheet issued by Denmark in 1975 (Scott 565, Figure 3). This sheet shows some of designer Martinus William Ferslew's essays from 1849 and 1852. An essay is a concept illustration of a stamp. Often the essay is not adopted or is radically changed from the issued stamp, but essays are avidly collected and are often.
The engraver W. FERSLEW, known from the first Danish stamp, has put his name on the 20 rigsbankdaler (DOP 70 and 90) in microtypes within the slanting down stroke of the N in No. in the number-field at the bottom. The artist Gerhard Heilmann has drawn his initials within the pattern on the 10, 100, and 500 kr. notes in the three Heilmann series.
Denmark 1872 Letter sent from Silkeborg to Copenhagen 27 July 1872 bearing a 4 sk. bicolored issue, tied by the rare “SILKEBORG J.B.” two-ring stamp and alongside, also stamped with numeral 225. 4 sk. with small faults, however very few examples of this rare postmark are known on cover. Danish West Indies 1917 Transition period 1917.