The only chemical that is absolutely required for processing POP paper is plain non-hardening fixer. Kodak RapidFix (without the hardener - part b) is a suitable product. Remember: only use part A of the product; the hardener will ruin a POP print by severely over-bleaching it. Dilute the stock solution with water to create a 1:7 working solution. Two fixing baths are recommended, using the typical rotation method to avoid exhaustion of the fixer.
If a print tone other than ugly orange is desired, a toner should be used. Here are several popular toning formulae:
Two-part gold thiocyanate
Stock Solution
Part A Part B
Distilled water 490ml Distilled water 500ml
Gold chloride 1% solution 10ml Sodium thiocyanate 10g
These stock solutions have an indefinite shelf life.
Working Solution
Distilled water 900ml
Part A 50ml
Part B 50ml
Upon mixing parts A and B the solution will turn a bright red color, which will quickly dissipate to yield a clear liquid. This is the working strength solution to be used for this session only, as gold thiocyanate is quickly rendered useless by oxidation. After toning each 8x10 print, add 8ml of each stock solution to maintain consistency. Tone print before fixing.
Gold borax
Stock/Working Solution
Distilled water 350ml
Gold chloride 1% solution 6ml
Borax 3g
Distilled water to make 400ml
This toner keeps well, may be reused and can be replenished. Experiment with different strengths of toner to expand or contract toning times. Tone print before fixing.
Selenium (Kodak RST)
Stock/Working Solution
Distilled water 500ml
Kodak Rapid Selenium Toner 1-2ml
Experimentation will be required to hone selenium toning, which can be finnicky. One is better off toning too slowly than too fast, so a low concentration is the prescription for best control. Fast toning in selenium can produce interesting split-toning effects. Tone print after fixing.
Pour toner and fixer into trays one size larger than the paper being used (11x14 tray for 8x10 prints). Ribbed trays may be used; however, the prints must be constantly agitated to avoid having bright lines form where the paper contacts the tray. Flat trays do not have this problem and are better for fully submerging the print, since, to avoid waste, small amounts of toner are used.
Processing POP
Rinsing - Once the print has been exposed to an acceptable level, remove it from the print frame and rinse it in running water. The water will be murky at first as unreacted silver salt is rinsed away. As it is rinsed the print will turn from a bluish-purple color to an orange-brown color as the reaction is stopped. This will probably take about 30 seconds but should be continued until the water is clear, as excess silver will quickly exhaust the toning solution. If a small print is being made on larger paper (and the dark edge will ultimately be trimmed away), trim any excessive dark border from the print. There is no point to using (and wasting) precious gold toner on paper, which is going to be discarded anyway.
Toning - After rinsing, slip the print into the toning solution, and watch for a color change while agitating. Usually toning times run anywhere from three to twelve minutes, with the longer times producing the coldest tones. The thing to keep in mind here is that the color of the print while it is in the toner has little to do with the ultimate color of the print. Watch for the amount of color CHANGE to determine when to stop toning. (Yes... more trial and error.) After a few attempts instinct will guide the process.
Fixing - Prints should be fixed in two baths of non-hardening fixer for approximately 5 minutes each. As they are being fixed, the prints will experience yet another color shift, which will closely resemble the look of the final print. Bear in mind that a considerable dry-down effect will impact the final look of the print. If a print looks great while sitting in the fixer, it is guaranteed to be too dark once dried.
Washing - Before washing, soak in a hypo clear (use Kodak HCA or one tablespoon EDTA plus one tablespoon sodium sulfite to a gallon of water) bath for two to three minutes. Wash prints for 60 to 90 minutes (only about 30 minutes is required if using hypo clear) in running water, preferably in an archival print washer. One of the undeniably great virtues of POP is that a properly washed print will outlive the artist who produced it (as well as his children and his grandchildren). Silver chloride prints exist today which were produced over 150 years ago and have withstood the rigors of time with amazing permanence. Hang prints to dry, and straighten in a dry mounting press.
Alternative toning methods - If selenium or gold toning AFTER fixing is desired, rinse and fix the print as described above, then fully wash. Once the print has been washed thoroughly, tone in either gold or selenium. Then wash again for another 30 minutes. This method of toning is not necessary for gold, but is absolutely required if toning in selenium. Keep in mind that prints produced using this method will be vastly different from those created using the standard method of toning. (The difference is in the point at which bleaching occurs.)
Consider toning with tea or coffee as well. Steep five or six tea bags (no need to use any elaborate blend; the standard orange pekoe will do fine) in a quart of water. Let cool, and tone away. Surprisingly teas and coffee are archivally permanent but may require extended washing.
If a print tone other than ugly orange is desired, a toner should be used. Here are several popular toning formulae:
Two-part gold thiocyanate
Stock Solution
Part A Part B
Distilled water 490ml Distilled water 500ml
Gold chloride 1% solution 10ml Sodium thiocyanate 10g
These stock solutions have an indefinite shelf life.
Working Solution
Distilled water 900ml
Part A 50ml
Part B 50ml
Upon mixing parts A and B the solution will turn a bright red color, which will quickly dissipate to yield a clear liquid. This is the working strength solution to be used for this session only, as gold thiocyanate is quickly rendered useless by oxidation. After toning each 8x10 print, add 8ml of each stock solution to maintain consistency. Tone print before fixing.
Gold borax
Stock/Working Solution
Distilled water 350ml
Gold chloride 1% solution 6ml
Borax 3g
Distilled water to make 400ml
This toner keeps well, may be reused and can be replenished. Experiment with different strengths of toner to expand or contract toning times. Tone print before fixing.
Selenium (Kodak RST)
Stock/Working Solution
Distilled water 500ml
Kodak Rapid Selenium Toner 1-2ml
Experimentation will be required to hone selenium toning, which can be finnicky. One is better off toning too slowly than too fast, so a low concentration is the prescription for best control. Fast toning in selenium can produce interesting split-toning effects. Tone print after fixing.
Pour toner and fixer into trays one size larger than the paper being used (11x14 tray for 8x10 prints). Ribbed trays may be used; however, the prints must be constantly agitated to avoid having bright lines form where the paper contacts the tray. Flat trays do not have this problem and are better for fully submerging the print, since, to avoid waste, small amounts of toner are used.
Processing POP
Rinsing - Once the print has been exposed to an acceptable level, remove it from the print frame and rinse it in running water. The water will be murky at first as unreacted silver salt is rinsed away. As it is rinsed the print will turn from a bluish-purple color to an orange-brown color as the reaction is stopped. This will probably take about 30 seconds but should be continued until the water is clear, as excess silver will quickly exhaust the toning solution. If a small print is being made on larger paper (and the dark edge will ultimately be trimmed away), trim any excessive dark border from the print. There is no point to using (and wasting) precious gold toner on paper, which is going to be discarded anyway.
Toning - After rinsing, slip the print into the toning solution, and watch for a color change while agitating. Usually toning times run anywhere from three to twelve minutes, with the longer times producing the coldest tones. The thing to keep in mind here is that the color of the print while it is in the toner has little to do with the ultimate color of the print. Watch for the amount of color CHANGE to determine when to stop toning. (Yes... more trial and error.) After a few attempts instinct will guide the process.
Fixing - Prints should be fixed in two baths of non-hardening fixer for approximately 5 minutes each. As they are being fixed, the prints will experience yet another color shift, which will closely resemble the look of the final print. Bear in mind that a considerable dry-down effect will impact the final look of the print. If a print looks great while sitting in the fixer, it is guaranteed to be too dark once dried.
Washing - Before washing, soak in a hypo clear (use Kodak HCA or one tablespoon EDTA plus one tablespoon sodium sulfite to a gallon of water) bath for two to three minutes. Wash prints for 60 to 90 minutes (only about 30 minutes is required if using hypo clear) in running water, preferably in an archival print washer. One of the undeniably great virtues of POP is that a properly washed print will outlive the artist who produced it (as well as his children and his grandchildren). Silver chloride prints exist today which were produced over 150 years ago and have withstood the rigors of time with amazing permanence. Hang prints to dry, and straighten in a dry mounting press.
Alternative toning methods - If selenium or gold toning AFTER fixing is desired, rinse and fix the print as described above, then fully wash. Once the print has been washed thoroughly, tone in either gold or selenium. Then wash again for another 30 minutes. This method of toning is not necessary for gold, but is absolutely required if toning in selenium. Keep in mind that prints produced using this method will be vastly different from those created using the standard method of toning. (The difference is in the point at which bleaching occurs.)
Consider toning with tea or coffee as well. Steep five or six tea bags (no need to use any elaborate blend; the standard orange pekoe will do fine) in a quart of water. Let cool, and tone away. Surprisingly teas and coffee are archivally permanent but may require extended washing.
