To close the loop from my original post, using curves from the P9000 ProK5 folder, I can confirm that using the Hahnemuhle Photo Rag Curves as the base for constructing personalized curves for Ilford Smooth Cotton Sonora and Smooth Cotton Rag worked very well, and for Ilford Textured Cotton Rag, I used the Canson BFK-Rives curve, which also performed very well. Perhaps the HPR curve could have worked well for it also, but this curve produced a very flat linearized curve superimposed over the ideal from 0 - 255. Similar excellent results were achieved for the other Ilford papers.
For those interested in these papers, I’ll share some preliminary data from my linearized Neutral Curve data set:
Smooth Cotton Rag: black: L14.01, D = 1.76; white: L 97.3, a* 0.09, b* 2.23
Smooth Cotton Sonora: black: L* 13.85, D = 1.77; white: L* 96.67, a* 0.00, b* 4.27
Textured Cotton Rag: black: L* 13.42, D = 1.79; white 97.26, a* 0.23, b* 1.04
By comparison using the Neutral Curve data set, Hahnemuhle Bamboo achieves a darker Dmax, 1.83, has lower white point L* 95.9, a0.33, b 3.55. Canson BFK Rives natural white achieves even darker Dmax, 1.86 and L* 11.86, with white point 97.35, a* 0.13, b* 1.88; Canson Edition Etching reaches black L14.58, D = 1.74; and white: 96.52, a 0.26, b* 0.65. Canson Rag Photographique has black L13.39, D = 1.79; white L 97.51, a* 0.28, b* 0.65.
I use all of these papers, and will do more work with the Ilford papers. The Sonora is quite warm and provides an interesting choice for selective images with a beautiful, refined finish, velvety in the hand. Likewise, the Smooth Cotton Rag provides a warmer alternative to Canson Rag Photographique and like the Sonora has one of the finest smooth finishes of any paper I’ve used. The Textured Cotton Rag is beautifully textured, very similar to Canson Edition Etching, but has greater warmth, yet remains on the neutral side by comparison with H. Bamboo and others. I’m particularly drawn to its possibilities as an alternative to Edition Etching.