I wondered about that and have now done it again with the following data results
How does this look to you
QTR-Linearize-Data version 2.7.5.0
File: /Users/ianbarber/QTR Curves/Pinnacle Cotton Rag 310gsm-out.txt
Step Dens Lab A B
0.00 0.040 96.50 0.00 0.00 - b L +
5.00 0.081 92.98 0.00 0.00 - b L +
10.00 0.132 88.85 0.00 0.00 - b L +
15.00 0.187 84.49 0.00 0.00 - b L +
20.00 0.259 79.08 0.00 0.00 - b L +
25.00 0.321 74.66 0.00 0.00 - b L +
30.00 0.388 70.12 0.00 0.00 - b L +
35.00 0.454 65.84 0.00 0.00 - b L +
40.00 0.526 61.44 0.00 0.00 - b L +
45.00 0.598 57.31 0.00 0.00 - b L +
50.00 0.671 53.31 0.00 0.00 - bL +
55.00 0.742 49.65 0.00 0.00 - Lb +
60.00 0.788 47.37 0.00 0.00 - L b +
65.00 0.883 42.90 0.00 0.00 - L b +
70.00 0.970 39.08 0.00 0.00 - L b +
75.00 1.094 34.08 0.00 0.00 - L b +
80.00 1.214 29.69 0.00 0.00 - L b +
85.00 1.336 25.59 0.00 0.00 - L b +
90.00 1.412 23.23 0.00 0.00 - L b +
95.00 1.498 20.75 0.00 0.00 - L b +
100.00 1.635 17.08 0.00 0.00 - L b +
LINEARIZE="96.495101 92.981415 88.849781 84.491689 79.077498 74.662569 70.122112 65.840786 61.442349 57.3101 53.310925 49.649033 47.366508 42.899787 39.082821 34.081111 29.693872 25.588358 23.230715 20.745073 17.07622"
For Digital Negative:
LINEARIZE="17.07622 20.745073 23.230715 25.588358 29.693872 34.081111 39.082821 42.899787 47.366508 49.649033 53.310925 57.3101 61.442349 65.840786 70.122112 74.662569 79.077498 84.491689 88.849781 92.981415 96.495101"