Jill, I don't know that I follow your reasoning. I have a different idea of how to accomplish this, you tell me if it is possible to accomplish judging from your experience. O.K.?
1. Measure the density range of the camera (photographic) negative.
2. Taking a Stouffer 21 step tablet, shoot an exposure of the step tablet to determine an exposure that will expose the density range of the camera negative onto the lithographic film that you are using.
3. Make an unsharp mask of the photographic negative. (typical peak density of .35)
4. Taking the camera (photographic) negative, and register this with a sheet of unexposed litho film. Shoot an exposure through the camera negative to cover the density range of Zones I-III (example of densities .10-.35). Process the litho film. This will produce a positive (high density) of the low density areas of the camera negative.
5. Contact print this litho positive with an unexposed sheet of litho film to produce a negative of this positive. (This will become the mask, when place in register with the camera negative, through which one of the print exposures (shadow) is made.
6. Take the positive litho mask produced in step 3 and register this with the camera negative. (effectively blocks low density regions of the camera negative) and another sheet of unexposed litho film. Shoot an exposure to cover the densities of .10 through 1.00) Zones I through VI. Since we have blocked the low densities with the litho mask previously produced only the camera negative densities of .35 through 1.00 will be exposed. This will produce a positive of the camera negative.
7. Take the positive produced in step 5 and register it with an unexposed sheet of litho film, expose it to produce a negative of the positive. This will become the mask through which the midtones of the camera negative are exposed when producing the print.
8. Taking a Stouffer step tablet determine exposure on the paper used to cover the density range of the camera (photographic) negative.
9. Take the positive produced in step 4 and the positive produced in step 6 and register them with the camera negative. Dial in high contrast filtration and expose the highlights of the camera negative onto the printing paper. The high contrast will effectively separate the high values which are placed on the characteristic curve of the film's "shoulder".
10. Take the negative produced in step 7 and the positive produced in step 4 and register with camera negative and expose the enlarging paper with lower contrast filtration then the previous exposure. This produces the midtone print exposure. Since the midtone densities reside on the "straight line" portion of the film characteristic curve, they are typically already well separated.
11. Take the negative mask produced in step 5, register it with the camera (photographic) negative and expose the enlarging paper with high contrast filtration to create greater separation of the shadow ranges. Densities represented on the "toe" of the films characteristic curve.
12. Make an exposure with the unsharp mask( step 3) in register with the camera (photographic) negative. To blend the various demarcations that may exist in the previous exposures and increase the prints apparent sharpness through edge effects.
I might add. That the print exposures previously addressed would need to be adjusted by the peak density value of the unsharp mask (typically .35). Since this exposure will be added in the last (step 12) exposure.
The effects of this means of printing are to defeat the characteristic curve of the camera negative and to also create much more tonal separation throughout the print. (Open shadows and well separated tonality in the highlights).
This is where I am in the process. As a person working in graphics materials, does this seem plausible?