Kallitype clearing

[Johnindc]

I haven’t seen this aspect of clearing kallitypes on any search so I hope this information will be helpful to some. I found that sensitized paper that was stored over night and exposed and processed the next morning would not clear under any conditions: new developer, old developer, more acidic developer, citric acid clearing bath. The unexposed areas under the mask would simply not clear. A newly mixed batch of sensitizer cleared completely in a couple of minutes in new developer as well as old developer.

My guess is the sensitizer, over time, reacted with the alkalinity of the paper forming iron hydroxide. The timeframe in my case was something under 18 hours. I’m using Lenox 100 paper and sodium citrate developer.

 

[Mark Fisher]

I found both Kallitype and Pt prints very difficult to clear with my water even with added citric or oxalic acid.....until I started using Permawash for my clearing bath at regular silver paper concentration. It actually checks near ph neutral with my water. I suspect other hype-clear solutions would work equally well.