Onion Skin Paper OVERPRINT.  The American Issue was printed by the American Bank Note Company in the USA as Denmark was still occupied by Germany in early 1945.
However, when Denmark was liberated it was decided to overprint the original set Scott #10-18  with “Danmark Befriet 5 Maj 1945”.  Original full sheets were to be overprinted.
Overprinting of the original set was done by the Commercial Stationery Company of New York.
However, there seems to have been some “accidental” overprint impression made on “slip sheets” .  The overprint was done in a blue color in the correct size that was used to overprint the high values – 30 ore, 1, 2 and 5 kroner values.  ONLY BLUE WAS USED.  The normal overprint color for the 1 kroner stamp was “red”.
Size of onion skin is 1 1/4 inches wide x 3/4  inch high.
This particular overprint on the slip sheet / onion skin paper is designated TYPE C and it larger than the one used for the smaller values.
This TYPE C is much scarcer and I have only seen them on the 1 and 2 kroner values – 2 times only to date.  Many not known to have survived.  Might have been 100 copies made at one time – 1 sheet like the lower values –
Some specialists have thoughts that these overprints may be “proof strikes”
Lot includes the stamp as well as the “Onion Skin” overprint
From National and International award wining exhibit.