| Designer | X1 | X2 | X1 = pH | X2 = T (˚C) |
| 1 | −1 | −1 | 5.0 | 40 |
| 2 | 1 | −1 | 8.0 | 40 |
| 3 | −1 | 1 | 5.0 | 80 |
| 4 | 1 | 1 | 8.0 | 80 |
| 5 | −1.41 | 0 | 4.4 | 60 |
| 6 | +1.41 | 0 | 8.6 | 60 |
| 7 | 0 | −1.41 | 6.5 | 32 |
| 8 | 0 | +1.41 | 6.5 | 88 |
| 9 | 0 | 0 | 6.5 | 60 |
| 10 | 0 | 0 | 6.5 | 60 |
| 11 | 0 | 0 | 6.5 | 60 |