I found this Wurttemberg Postal Stationery cut square (on the left in the attached pictures), and thought it was kind of odd looking.
In pictures, I have the cut square in question, and what I think a normal one looks like.
In this first picture, you can see the "front" I guess? I say that because that's the side that has the cancel. I guess the printed words are a cancel too? I saw covers online that had those words across the corners but I don't know what it is/what it's for. I think it says "POST-COUVERT DREI KREUZER". The front seems to have a mirror impression (everything is reversed) of the right cut square, and has a faint pinkish tinge in the imprinted area.
In the second picture, you can see the other side in comparison to the front of the correct cut square. You can see the frame upraised, and the numeral "3" in the center is now correctly oriented and is upraised (I think how it should be). There does not seem to be any hint of color on this side.
Does anyone know what this is? Is it listed somewhere?