Mind the gap - again

Yesterday, Ted McClelland of 20x24 performed some experiments, of which this is one, showing the effect on the negative of too-thin a reagent gap, and what happens.

In the upper left, there is sufficient gap for smooth and complete processing with no solarization after pulling either. On the lower right, the mottled appearance is where the reagent was exhausted before the process was complete, resulting in an uneven appearance.  All this matters to the construction of the pod, and the rails.

The difference between these two areas in terms of thickness is slight, perhaps a tenth of a mm, or less.

Other artifacts that look like little wings if you zoom in close are the receiver sheet top coat pulling away from the substrate. This happened, I think, because we over humidified the receiver, which has been severely curling on us due to the very dry weather.

Summer was a better time to build New55. Our lab is not climate controlled, and there is no way to humidify it.