Salt

The Calibration print shows a modest toe before a long and even transition to Dmax. However, testing indicated a distinct shoulder before Dmax, resulting in the symmetrical curve shown in the plot window.

There were problems with what appeared to be a base chemical fog, which downgraded the whites and muddied the prints. This was eliminated by not using a dryer and letting the sensitized paper dry naturally. The Platinum Rag was pre-soaked in a 5% salt and 1,5% citric acid bath, then leaving it to dry overnight and processing in a 5% salt solution.