Does the Choice of Printing Paper Inluence Print Graininess?

By Dick Dickerson & Silvia Zawadzki Back to

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There are a number of off-the-cuff responses that would seem, on casual consideration, to afford a clear cut yes or no answer to the title question. But the factors that contribute to print graininess are manifold. Below we consider each of them individually to appreciate their interactions and consequences— and to highlight a lesser known but significant path whereby paper choice can indeed influence print graininess.

One factor is of course the negative’s graininess. Grainier negatives produce grainier prints. QED. We will remove this from the present discussion by restricting our attention to a single negative printed on various papers. The degree of enlargement is relevant as well. The more a negative is enlarged, the grainier the resulting print. So we will further restrict our attention to a fixed negative printed at a fixed degree of enlargement on different papers.

Paper grain

One might wonder if paper graininess, like film graininess, is a contributing factor. There are two reasons it is not. The emulsions used to sensitize paper are much finer grained than the far faster emulsions used to make films. Couple this with the fact that, unlike the negative, there is no enlargement or magnification of the paper’s emulsion in the workflow, and the paper’s emulsion grain drops off the list of contributing factors.

Our eyes, or more properly, our visual response, is yet another issue playing a key role. Graininess is, after all, a purely subjective phenomenon. Granularity on the other hand is totally objective. It can be measured with instruments and a numeric value assigned to it. Graininess is the visual appearance of granularity and depends in no small measure on how our visual system is wired. Graininess is the appearance of nonuniformity due to small density fluctuations (granularity) in what would otherwise be a smooth area of uniform density. We are much better at seeing small density fluctuations in lighter areas than darker areas. Consider that a small variation in density in a print’s highlights is distinctly visible while that same variation in a middle gray or darker area of the print would go unnoticed. This visibility factor, all by itself, would make graininess most evident in the lightest areas of a print.

But there is another factor competing with this, and that is the printing paper’s instantaneous contrast (IC) as revealed by its characteristic curve. At its mini- mum density (blank white in the print) the IC is zero—there is no contrast. As exposure increases and moves into the curve’s toe (highlights) IC begins to increase. As exposure increases more the curve enters its straight line portion and IC reaches its maximum value (middle grays). At yet higher exposures (dark tones, eventually shadows) the curve rolls into its shoulder and IC again begins to decrease, returning to zero at Dmax (empty blacks).

Grain and characteristic curves

Here is the important point: The IC acts as an amplifier on fluctuations in the negative’s density (its grain). At an IC of 0.5, somewhere in the toe and again in the shoulder, any fluctuation in negative density appears as a density fluctuation only half as great in the print. At an IC of 2.0, approaching the curve’s straight line portion, depending on paper grade, any density change in the film reproduces as twice that change in the print. Thus as print density increases from blank white to lower middle gray print granularity is constantly increasing—but at the same time, because of the visibility factor, it is becoming increasingly difficult to see as graininess.

The end result of the competition is this: Our awareness of print graininess typically peaks at about the point the paper first enters its straight line portion. At higher densities IC is no longer increasing but grain is becoming more difficult to see. At lower densities it is easier to see but is not amplified as much.

Herein lays the influence of paper choice on print graininess: Print the same negative at the same magnification on two papers of identical grade number but differing curve shapes. The paper with the shorter toe that reaches its maximum IC at the lower density will yield a grainier looking print. A pair of such curves is illustrated in the accompanying graph. Of course the grainier print will also have snappier highlights, which, depending on the image, may or may not be an advantage that may or may not outweigh the impression of more grain. Another of the many trade-offs in the photographic process. Which paper makes the better print? That’s a decision for the photographer.


About the Author

Dick Dickerson & Silvia Zawadzki
Contributor
Dick Dickerson and Silvia Zawadzki are retired Kodak black-and-white product builders who have authored numerous articles for PT. They can be contacted at querybw1@aol.com. Dick and Silvia reside in Rochester, NY.