This postal stationery card was released in 1941. it was issued in 3 denominations, of 5 Reichspfenning, 6 Reichspfennig and 15 Reichspfennig. This 6 Rpf. denomination was commonly used for postcards sent within Germany. There was a lot of variation in the shade of the ink used on this simple, single sided postal card.
Here is a PDF of this card.
This postcard for occupied Poland was introduced in 1944.
Here is another, earlier postcard from the Generalgouvernement (Nazi-occupied Poland). It dates from 1940 and is bilingual, German/Polish. This one does not have the postage pre-printed; the user had to apply an adhesive stamp with the correct rate.
The originals are printed on a very thin card stock, almost a heavy paper. It’s likely they were off-white originally and have yellowed from age.
Thanks to Dylan Wickstrom for his invaluable help in creating the printable reproductions.