RE: Mike Ware's POP Pt./Pd. Pt
Loris, It appears that the white, irregular spots I described earlier resulted from using too little of the sensitizing solution. With this method the paper seems to need about 20-25% more solution than with DOP Pt./Pd. In any event I increased the amount of solution for the coating area, and added a few drops of a surfactant, and today made four very nice 12X17" prints with the Ware POP method, with no irregular spots. I am very pleased with the good Dmax I am getting with this method at RH of about 55%, and the color of the prints is a nice warm sepia, not unlike what you get with warm potassium oxalate in DOP. Sandy King At 8:35 AM +0200 11/10/06, Loris Medici wrote: Hi Sandy, What is your coating / drying procedure? -----Original Message----- From: Sandy King [mailto:sanking@clemson.edu] Sent: 10 Kasžm 2006 Cuma 08:23 To: alt-photo-process-l@usask.ca Subject: RE: Mike Ware's POP Pt./Pd. Pt One issue I have seen with a few of the AFO PT./Pd. is small white spots, irregular in shape and some larger than others, and all in the shadows and lower mid-tones. I suspect that they may be caused by the sensitizer separating from the paper during exposure, or more likely when the negative is separated from the paper after exposure, perhaps due to moisture content. I use a vacuum frame and the pressure, even though not great, may cause the separation. With FO Pt./PD I typically dry the coated paper only about fifteen minutes and have never had this kind of issue. With the POP process I am finding that there is some risk of the white spots unless drying times are much longer. As I mentioned earlier, I am working in a room with RH of about 50-55%. Of course, the problem might be something else, such as something in the sensitizer or method of coating. I am very new to this method of printing and still trying to learn to recognizes the cause of problems.
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