Letter cards were introduced in Denmark
in October 1888.
8 øre letter card upfranked with 3 x
5 øre sent to Brazil.
5 on 4 øre letter card sent as printed matters to
The perforation is found in four different
main types: Perforation 9½, 11 1/4, 10 3/4 and 12.
See examples from my
collection of letter cards.
Before issueing letter
cards in 1888, some essays were made.
As written on the edge, the normal
use of the letter card will be to tear off the edge of the letter
card when opening it. But some cards were opened with the edge being
intact. These letter cards are scarce and the value is higher than
used letter cards without the edge.