an overview of masks: what they are; what they do. Masking is selective dodging.. consider it a precise, custom, graduated neutral density filter. Masks are most often used this century to alter contrast of B&W film. They also increase local contrasts, thereby altering edge effects making a print appear sharper with more gradations. These are the “unsharp masks (USM)”

In last century, during the growth stage of masking, they were used in color processes to alter, and correct contrast and color. Masking increased the contrast of the magenta and yellow, overcoming deficiencies, impurities of colorants.

If the original transparency isn’t underexposed, and the contrast of the scene is low, no masking is required.

Films I have today for masking: Ilford PanF (120). Ilford Delta 100 (4×5 & 8×10). Ilford Ortho+ (4×5, 8×10, special roll). Note the Ilford weight. I do, and it makes me nervous, since Ilford hangs on the interest of real estate ventures in a country of short term values.

From the past; more for the Rosetta stone. Translating data sheets. Why that film/developer was made.

Masks should never be greater than 40%. Coated (APO) lenses require higher percent masks.

The appearance of color swatches in separation negatives is best indicator of correct mask exposure.

Most of the original guidance assumed the use of the Standard Light.

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Developer for masks, like those for seps should be non-staining and not “fine-grain” solvent type. It is easy to recommend DK-50, DK-60a as best options, even this decade. For ready mix, try HC-110 one-shot. All masks and seps should be processed following a one-shot protocol. Use the mixture one time and discard. I use fresh developer for each sheet of film.

Filter	Use
F- 29 Red	Required
N- 61 Green	Required
#96 Neutral density: 0.10 / 0.30 / 1.0	Strongly recommended. Equalize exposures. Reduce reciprocity differences.
#33 Magenta	optional
#15 Yellow	optional

Be assured that masking cannot make a color that the dyes, if mixed outside the system, cannot produce. This is why we always tried for better and better dyes (colorants). To correct all the cross-talk of dyes, six masks are needed. Contrast of masks is proportional to errors of colorants being modified.

compensate blue and green in CYAN	2 masks
compensate for MAGENTA	2 masks
compensate for YELLOW	2 masks

Not a realistic effort. Particularly since most images/ viewer sets can’t discern the improvement in real world conditions.

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MASKING COLOR NEGATIVES

footnote for ongoing readers: notation on confused Large format masking board:

Removing the “Orange” mask: If you want this brightest color to have a neutral hue, you need to expose, such that Dred = Dgreen = Dblue = 0.9, i.e. a uniform gray strip with D = 0.9 will be the brightest neutral color you can create. With extra exposure you can then reach all colors in the range (Dred = 0.9, Dgreen = 0.9, Dblue = 0.9) + (ΔDred, ΔDgreen, ΔDblue) with ΔDred ≥ 0, ΔDgreen ≥ 0, ΔDblue ≥ 0.

There was no magic in separation negatives. It has always been a balance between exposure types, filters, film + developer + agitation method.

I rarely used Super-XX as a sep film; only when clients required it. And on a small year, I made around 200 first prints – this, during my first 5 years working.