Chrysotype notes

Troubleshooting. A practical example

One of the curses of certain alternative processes is called the 'black plague'. Platinotypes and chrysotypes are prone to this and it shows as multiple black spots which appear on prints With palladiotypes I worked out that it could be avoided by not leaving the exposed print in the potassium oxalate developer for too long (30 seconds was enough) but when I fell foul of this with chrysotypes they appeared when the print was in the first clearing bath, i.e. after the developer. When any problem appears it is common practice to break the process down into all its stages and only change one thing to see if that resolves the issue.

A small rewind, here, to explain how this all came about. Whilst reading through Leanne McPhee's invaluable book on chrysotypes I spotted a comment by Marek Matusz where he stated that instead of the three clearing baths he used a single one which was a solution made up of Na4EDTA and citric acid. This appealed to me due to its simplicity so I decided to try it and exposed a test print on Bergger COT320, which was my paper of choice. The print went well, developed cleanly but as soon as it entered the clearing bath the black spots appeared. Now I was faced with a large number of steps which would need to be isolated but read that with chrysotypes the normal solution is to increase the ligand in the sensitiser mix. Tried this and saw no difference. I dropped an email to Marek who responded that the problem was the paper but I knew that I had run half a dozen prints with paper from the pack and had had no problems - I also know that this is the common answer to problems with palladiotypes but I was using a different process. Putting it down to Marek being too busy to read my email properly and me just knowing better (I didn’t) I decided to set about solving this problem. Here are the stages which were carried out:

Print 0: this is the print where the problem first appeared. The paper was Bergger COT320 and I was using a normal ratio of 4:4:1 version S chemicals. The humidity was ambient and hovered between 65% and 68% during the time that these steps were taken. The temperature was in the 20C to 22C range. All prints were off the same negative and exposed for 90s. Developer used was 1% oxalic acid solution

Print 1: increase ligand so the ratio was 6:4:1. No change

Print 2: Change back to Na4EDTA, Sodium Sulphite, Na4EDTA clearing baths. No change

Print 3: Marek suggested trying citric acid developer. No change.

Print 4: Marek suggested filtering the ammonium iron oxalate solution (the last number in the ratio). No change

Print 5: Try chemicals from a different source. I have been using my own chemicals up to this point but did have some from Gold Coast Studios so made a print with these. No change

Print 6: Due to the way I work I have been using hot water to make sure that my chemicals are fully dissolved. I reasoned that the common factor amongst the prints was the raised solution temperatures so made them with cold water. No change apart from a colour shift.

Print 7: Saw some black residue in my trays so gave them a good clean. No change

Print 8: Finally decided to try a different paper. Switched to Hahnemühle Platinum Rag . NO SPOTS! It was the paper, all along.

When the black plague strikes it means that you no longer have confidence in that paper so I have now switched to HPR for all my prints. The problem with this change is that the colour profile changes due to the sizing used on the paper and this has now meant a much deeper investigation into humidity. But that, as they say, is a whole other story.

It would wrong to claim that this process was carried out in isolation and I had constant communication with two chrysotype printers. The first was Marek, who has already been mentioned, and the second who has not is Paul Walding. Marek always found time to respond to my emails with suggestions – in fact his first one was the right one but I chose to ignore it. Paul was instrumental in helping me to clarify my thought processes to solve this problem and always eager to offer helpful advice and encouragement.