Searching for the ideal shortbread

Cooked with increasing amounts of fat (top to bottom) and sugar (left to right). The best two shortbreads are highlighted green; the best cookie, orange. The 62.5% shortbread is almost as good as the 75%.

			Sugar
100%	flour	Butter	25%	62.5%	75%
		50%	1	2	3
		62.5%	1	2	3
		75%	1	2	3

50% fat

1. Cheap shortbread 
2. Too hard
3. Almost inedibly hard

62.5% fat

1. Nice, yields easily
2. Slightly more chewy
3. Too hard

75% fat

1. Yields even more, disappears to nothing in the mouth
2. Chewy, a good cookie
3. Slightly too sweet, not unlike the supermarket bakery cookies