I think people may be misreading this. I think these filters are in standard color correction values, not variable contrast filters. I'd start out trying combinations equivalent to the manufacturers suggested values for each grade using a dichroic head. Those values should be in the instructions that came with the papers. You may have to add a number of filters to get those values, and yes, if you have the correct combination of values, you could go between the standard grades. You should also be able to do split grade printing with two exposures and the suggested values for grade 0 and grade 5.
For suggested Ilford values see: http://www.ilford.com/html/us_english/pdf/Cont.pdf
Edit: I'd second Ed's recommendation of the Anchell book. I think I'd find it more work to shuffle a stack of CP filters through a series of tests for contrast than to do one switch per print with split filter printing, and likely harder to keep track of. But as everyone does, you'll have to find what works best for you.
Last edited by Lee L; 03-16-2006 at 12:01 PM. Click to view previous post history.