Very nice cancel on this one , a keeper.
The stamp itself features the ruins of the castle at Bedzin & was issued December 1946 as a definitive. It was printed in two colours, olive & brown, though the shades of each are quite varied. Total printing for both colours is about 98.5 million so it's not the most valuable of stamps although you can make a nice page showing the shade varieties.
The stamp was issued imperf. although there are heaps of private perfs
