Bogen om julemærkets posthistorie (The Book on the Postal History of the Christmas Seal) by Ole Steen Jacobsen, 6-1/4 by 9-3/4 inches, 96 pages, hardbound, in Danish with English summary, published by the author in Denmark, 2001, ISBN 87-985542-3-9, approx. $40.
In 1904 Denmark introduced the Christmas seal to the world. Prior to that time there had been other types of charity seals, and the English post office in Rochdale had a special Christmas cancellation in 1902. The Danish seal was invented by the Danish postmaster Einar Holbøll, who worked at the office in Gentofte and later Charlottenlund.
Sweden and Iceland also introduced Christmas seals in 1904 and other countries followed later. At first the seal was to be placed on the back of the envelope, but in 1941 in Denmark, permission was granted to place them on the cover front, thus creating the opportunity for tied seals.
The serious student of Christmas seals can study them just as postage stamps, with analysis of proofs and essays, gum, paper, watermarks, perforations, cancellations, and formats such as sheet, booklet pane, and souvenir sheet. The book lists the date of issue for each seal (yes, people collect FDCs of these seals), and the quantities printed.
Collectors search for usage on unusual mail such as COD matter and Sunday letters. All of the Danish seals are illustrated in color, and in fact many color illustrations throughout this handsome book make it a joy to look through. The illustrations carry captions in both Danish and English. A bibliography concludes this well presented book.