The Amazing Disappearing Spot

[tgtaylor]

Everything was looking fine until the 2d clearing bath with EDTA. Then out of nowhere a large brush like spot - a lighter shade than the sky - appeared in the sky on the top left of the print. At first, I thought that I had poured the EDTA bath directly on that area instead of distributing it like I normally do. It remained throughout the 5-minute bath appearing to decrease in size slightly. Then another spot appeared under the first spot, again in the sky area, but this one was circular like a bottle cap. Against good judgment I decided to tone the print anyway just to see. As soon as the platinum toner hit the print the spots went away without the slightest trace of ever having been there and the sky toned to a perfect uniform slate gray throughout. I've experienced this phenomenon in the past with other alternative printing processes, but they are rare. A google search for the cause turned up blank. The paper was HPR and Kallitype was the process.

Thomas

[martiansea]

I've never had this happen with the handful of kallitypes I've made, but I did experience an odd unexpected color changing sort of splotches when clearing argyrotypes that would eventually disappear over time after being dried.

[Erik Larsen]

I have had similar experiences Thomas. My non scientific diagnosis is that it is an anomaly in the paper size or a manufacturing defect. All’s well that end well though.

[tgtaylor]

Another one appeared today while printing a different negative. This time it was a small diagonal in the sky area cutting across the top left corner of the paper where the negative ends and where it would be easy to trim off when mounting. I noticed it at the very end of the 1st wash and it persisted throughout the 2d (EDTA) wash and the wash before toning. As I expected it disappeared without a trace as soon as the platinum toner hit it. The slate grey/platinum tone of the sky is uniform throughout so no silver/iron particles were removed. Could it be that the reflectivity of those particles in that area where somehow affected but restored by the toner?

Thomas