The stamp and primary postmark are on the front of the card.  On the reverse, the printed attribution “J.H. Schaefer’s Kunstchromo, Amsterdam. 90/64” and if you can interpret this date inside the reverse postmark, you will know when the card was mailed:  12.7.15.8-9N.  We think this means 1915 so please let us know if that’s not right.  Grade: 2