Two complementary sheets of any black/white Pattern should suffice. With some space between. That would get you 25% of ambient and zero from one specific direct

Two complementary sheets of any black/white Pattern should suffice. With some space between. That would get you 25% of ambient and zero from one specific direction. Make the inside of the outer layer and the outdid of the inner layer reflective and you could approach 37%. Spacing can be very close, but requires a smaller feature size. Regular patterns will cause moire patterns.