In The Postal Bee was published a South Korean stamp with a bee in offset.
The author of the book "Apiculture" the South Korean Seo-Yong Kim, called it mirror print.
Later I found something comparable on a stamp from Irak.
However : according to Mr. A. van der Flier in his book "Philately from A till Z" this phenomenon is not a mirror print.
Is said a mirror print occure when a colour on the stamp is unclear. To intensify that colour the same colour was printed in reflection on the back of the stamp. Probably there is one Austrian stamp (Yvert l a) known with this mirror print.
What we show here with the South Korean stamp and the Iraquian stamp is called "Abklatsch". Replacing the paper ink can come on the plate or the roll and that wet ink will be printed on the back of the next sheet.
by Jan de Crom
taken from "The Postal Bee" 1/2009
Contact Group Bee Philately