The Panther MkV was perceived by many as the best all around tank that the Germans built during the 2nd World War for its combination of speed, mobility, and firepower. Yet this tank had an improved armor design that made it a match for Russian tanks. What was so special about this armor innovation and where did the idea come from?

Sorry, don't know why the armour was "special", but the MkV Panther was a direct copy of the Soviet T34, the tank the MkV was commisioned to fight on the eastern front. The armour was lighter than previous German WW2 tanks.

Well it wasn't a "direct" copy but was based on the design of the T-34. Hilter and the German designers would never have permitted a direct copy and German manufacturing techniques and innovation were quite different. Since you are close enough, the thing that made the armor special on both models was that it was "sloped". This meant thatt the same thickness of armor could be used on the tanks but would have nearly twice the protection since shells tended to deflect more on impact and the resultant relative thickness of the armor due to the increased angle. Good answer.

Ahh, thanks. I was going to say the armour was sloped, but I wasn't sure if that was unique to the panther. Thanks.