How to verify that I fixed properly and washed properly

Discussions in this forum have impressed upon me the importance of fixing properly and washing properly. That discussion was about prints, but I assume the same applies to film negatives.

(1) Fixing properly --- My current strategy has been to do a "clip" test to see how long it takes for a fixer to make the film transparent and then do the fixing step for at least twice as long, up to a maximum of 5min, at which point it's time to replace the fixer. In the specific case of darkroom prints, some people do a 2-bath fixing, splitting the fix time equally between two baths. The first bath does the heavy-lifting and the second (fresher) bath helps ensure that there aren't any fixing byproducts on the paper. When the clip test hits 2:30, dispose of bath 1 (safely), bath 2 becomes bath 1, and you make a new bath 2. ---- Does this sound like a good enough strategy?

(2) Washing properly --- I was thinking of perhaps grabbing the Photographer's Formulary Residual Hypo Test.

I should mention that I'm only printing on RC papers which are easier to wash than FB.

Fixing for film you can check time to clear and double that, but the same doesn't hold true for paper, you can't watch it clear.

FB paper needs an hour to wash, but RC paper doesn't.

You could use the hypo test from Photographer's formulary. I bought it but haven't cracked the shrink wrap on it yet.

The biggest problem I've had with fixing is getting excited and doing a lot of prints at once, not paying attention to them in the fixer tray.

That and trying to go too far on too little fix concentrate. For example, using a few ounces concentrate to make less than a quart of fix and using it for a dozen prints.

Whenever I get sloppy or lazy I run into problems.

I used to have similar problems with washing, when I had a tray with a Kodak Tank and Tray siphon. Most of the problems happened when I made more than a half-dozen prints and didn't carefully monitor the washing.

Now I have an archival washer so I don't have that problem anymore.

But I still get ahead of myself when fixing prints in sessions where I make more than just a few prints.

Bill Burk said:

Fixing for film you can check time to clear and double that, but the same doesn't hold true for paper, you can't watch it clear.

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I was hoping to use film to test the paper fixer too. I mean... chemically they're doing the same thing. Right?

dcy said:

I was hoping to use film to test the paper fixer too. I mean... chemically they're doing the same thing. Right?

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Oh that’s an interesting trick. It might work

Here’s something worth getting

1. With modern films the "double the clearing time" should probably be triple the clearing time (not double). And when the clearing times are twice what they were with fresh fixer it's time to make a new batch. Use your film leaders for this and make notes of clearing times.
2. You can test for "retained" silver in both film and paper emulsions, you can go fancy and make a reagent or just use selenium toner.
3. There's a similar test for fixer. Blot the print and put the solution on if the drop tuns dark there's still fixer in the paper (obviously a good use for test prints or prints spoiled some other way).
4. I've never liked fixer test solutions, especially with rapid fixers the test can only warn you AFTER your fixer has failed. There are also hypo test indicator strips, sort of like pH paper for silver in a fixer solution.
5. You should have separate fixing working solutions for paper and film since the fixing by-products can be different and the dilutions for working strength are also different.
6. Tally marks on a piece of tape affixed (no pun intended or was there) to your fixer bottle never fail, one mark for every 80 sq. inches of film/paper.
7. Capacity of most fixers is about 20 8x10 per liter/qt. When in doubt be conservative.

Info on all of this is in The Craft of Photography by David Vestal, The Darkroom Cookbook by Steve Anchell), and The Film Photography Cookbook by Steve Anchell and Bill Troop. Probably in dozen's of other reference books, too, but those three are pretty easy to access.

Bill Burk said:

Here’s something worth getting

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Much better than those dropper "hypo" test solutions.

I check my fixer with Edwal Hypo Check, as long as the fixer tests as non exhaustion, or good, I do like you do I check film and double the time to clear. With paper, as long as my fixer is good I follow manufacturers recommendations, with FB I only use standard fix as over fixing is more of an issue and rapid fix I find is easy to lose track of time and over fix. With FB I use PF hypo residual check, with RC, in my work flow not as touchy just follow directions. Of the 1000s of print I have dating back to the 60s only a couple, and just that less than 10, are failing or faded to due to poor fixing.

Bill Burk said:

Oh that’s an interesting trick. It might work

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I just thought of a problem with my idea: For paper the fixer is often more dilute than for film. I'm using Ilford rapid fixer. For film it's 1+4. For paper you can use that, or 1+9.

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EDIT: Doesn't mean that my idea can't work. But I'll need to think about it a little bit. I could adapt @darkroommike 's advice: Test the clearing time with fresh paper fixer and when then clearing time doubles, it's time to replace the fixer.
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Strangely, for paper the capacity of the working solution is the same for 1+4 and for 1+9. I suspect that the reason must be that the limiting factor is not the fixing agent but the water solubility of silver halides or some other byproduct.

Bill Burk said:

Here’s something worth getting

Click to expand...

Oohhh... I didn't know those existed. I just found it on Amazon. The cost works out to $0.50 per strip. That's alright if you consider that you don't need to test the fixer every time you use it.

EDIT: The Ilford rapid fixer instructions say that for RC paper you can safely use fixer with 4-6 g/L of silver. This test strip you found is perfect for measuring that.

The reason that the capacity of prints per litre of working strength is the same for both 1+4 and 1 +9 is that the controlling factor is how much silver + halide load is in that partially used litre of working strength fixer.
Once there is too much silver in there, it can't do a good job fixing.

With RC prints, just follow the directions - being sure to agitate the prints a lot, and to protect them against sticking together in the fixing tray. Given how quickly they fix, it makes sense to minimize the number of prints in the tray at any time.
When our Darkroom Group does a group printing session, we use two bath fixing for both FB and RC prints, and all share responsibility for agitating the prints in the fixer and moving them along from tray to tray. It is a lot simpler if you just have your prints to concern yourself with.

MattKing said:

With RC prints, just follow the directions - being sure to agitate the prints a lot, and to protect them against sticking together in the fixing tray. Given how quickly they fix, it makes sense to minimize the number of prints in the tray at any time.

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Yeah. I currently do 1 print at a time.

@darkroommike Thanks for the tips! I do have a follow up question:

darkroommike said:

1. You can test for "retained" silver in both film and paper emulsions, you can go fancy and make a reagent or just use selenium toner

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What does selenium toner do in this context? My understanding is that toner is not a replacement for proper fixing and washing.

dcy said:

@darkroommike Thanks for the tips! I do have a follow up question:



What does selenium toner do in this context? My understanding is that toner is not a replacement for proper fixing and washing.

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A drop of selenium toner in the margin of a print is a good test for proper fixing: https://www.photrio.com/forum/threads/selenium-toner-as-fixer-test.68246/

dcy, I personally don't go to extremes with testing. Particularly with RC paper. It is much less fussy about fixer & washing time. I don't get critical with test prints.... once I'm doing work for clients (always on FB paper)....or big or exhibition prints,... then I am more critical about wash time & using washaid. YMMV..... (if you're learning how to print, there's a lot of prints as you likely already know, won't pass the harsh-light-of-day test.)

MattKing said:

A drop of selenium toner in the margin of a print is a good test for proper fixing: https://www.photrio.com/forum/threads/selenium-toner-as-fixer-test.68246/

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Excellent. Since I already bought selenium toner, I'll just use that.

Question: How long does selenium toner last? I bought the Kodak one, but it doesn't say. The Harman one says that the working solution lasts 6 months in a well-sealed container. Neither one says how long the concentrate lasts in a half-full container.

GregY said:

dcy, I personally don't go to extremes with testing. Particularly with RC paper. It is much less fussy about fixer & washing time. I don't get critical with test prints.... once I'm doing work for clients (always on FB paper)....or big or exhibition prints,... then I am more critical about wash time & using washaid. YMMV..... (if you're learning how to print, there's a lot of prints as you likely already know, won't pass the harsh-light-of-day test.)

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Absolutely. This is just to have a method to sporadically check that my fixing & washing routine are ok.

dcy said:

Question: How long does selenium toner last? I bought the Kodak one, but it doesn't say. The Harman one says that the working solution lasts 6 months in a well-sealed container. Neither one says how long the concentrate lasts in a half-full container.

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Arguably, forever, if you use and then essentially replenish a working solution.
Perhaps @Doremus Scudder will chime in on this.

dcy said:

Excellent. Since I already bought selenium toner, I'll just use that.

Question: How long does selenium toner last? I bought the Kodak one, but it doesn't say. The Harman one says that the working solution lasts 6 months in a well-sealed container. Neither one says how long the concentrate lasts in a half-full container.




Absolutely. This is just to have a method to sporadically check that my fixing & washing routine are ok.

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I have a gallon jug of selenium toner (1:19) and every now & then i filter it through a coffee filter to take out the sludge, and occasionally add to it as the paper tends to absorb some. This year i mixed a new batch.... but it had been a long time.....
(& I always warm it up to 30°C) otherwise toning with cold (temperature) is a slow process....especially with Ilford paper.

Selenium toner that's reasonably strong will last forever with a little replenishment. I use rapid fixer for in the film strength, check Ilford out for exact time. My work flow is after fixer, quick 60 seconds in water then straight into Kodak Rapid Selenium Toner 1+3, no staining at all if you use fresh fixer. Test strips like the fancy German ones as shown are great but are Expensive! You can buy a lot of fixer for what those strips cost.

I just impulse purchased some of these test strips from an Amazon seller, just shy of 50 usd. I doubt I'll ever use them . Still they're cool.

Fixing film : you can make it as complicated as you want, using techniques aimed at large commercial labs (two bath system, regular tests and monitoring..) and sure it'll work. Or, you could read the manufacturer already conservative guidelines about capacity and time compensation and be even more conservative. As long as you keep track of how many films were fixed in the solution there's no worries to have about underfixing nor tests needed.

Washing film : same thing, as long as guidelines are followed there should be no worries. That being said, the famous Ilford method to wash with minimum water (filling the tank with water , 5 inversion, dump, fill, 10 inversions, dump, fill, 20 inversions, dump) has been critized. If you search here on photrio, apparently the original technique indicated rest times between dumps to be the most effective (5min ? don't remember and I'm on mobile not convenient to check right now)

Perma wash is great

I'll wade in here too. First, however: dcy, you really should search here and over on the LF forum for answers to your questions. There is a ton of information on both sites just for the Googling.

Now to your questions:

Fixing film:
There are two strategies here. The first is to do a clearing test before each batch an ensure that you fix for a minimum of twice the clearing time. Actually, with more complex emulsions these days, a 3x factor is likely good.

The second strategy is to do a clearing test in fresh fixer with a given film and then fix the film for 6x the clearing time. What this does is use the correct time for the fixer at the end of its life. Yes, you fix some film for longer than absolutely necessary, but, with film, this is no problem. Then you don't have to do a clearing test before each batch, only when nearing the end of the fixer's capacity to find when to discard your fixer.

Important: In either case, you need to discard your fixer when the clearing time in the used fix approaches twice that in fresh fix. There are tests for adequate fixing and washing that I'll address later.

Fixing RC paper:
Use the manufacturers' throughput capacity suggestions. You'll be plenty safe here, since the manufacturers build in a generous safety factor. Overfixing RC paper isn't much of an issue either, since, like film, the fixer can't soak into the substrate. There are tests for adequate fixing and washing that I'll address later.

Fixing fiber-base paper:
Here's where it gets more complicated. Again, there are two strategies.

The newest is Ilford's archival sequence. There's a website dedicated to it, so I won't go into detail. It depends on using stronger dilutions of fixer for a shorter time, which can result in shorter wash times. Here's the website: https://www.ilfordphoto.com/ilford-optimum-permanance-wash-sequence-fb-papers/

The older (and time-tested) method for fixing fiber-base papers uses a weaker dilution of fixer for a longer time, usually in conjunction with two-bath fixation. I still find this the most economical and convenient. Fixing times are longer and the subsequent wash is longer too.

With a one-bath fixing regime, fixer capacity is less. A two-bath regime can double your fixer capacity whichever of the above methods you choose to use.

Whichever method you decide to use, a wash aid (Hypo Clearing Agent or similar) is an indispensable step when processing fiber-base papers.

Capacities: Here you need to decide how permanent you want your prints to be. There are generally two standards: commercial or general-purpose and optimum permanence. If you opt for the latter, you'll find that capacities are reduced. For example, Ilford gives 30 8x10-inch prints per liter for the commercial standard, but only 10 8x10-inch prints for optimum permanence in a one-bath fixing regime. (Note, these capacities can be increased by using two-bath fixation).

The easiest way to deal with capacity is to use the manufacturers' recommendations. If you want to be more hands-on, there are tests for both adequate fixation and washing.

Washing time for fiber-base prints varies with the fixing method. Personally, I like longer; a 10-minute treatment in a wash aid followed by a 60-minute wash in an archival washer.

ST-1 and Selenium Toner Tests for Adequate Fixation.
You can search for the formula or buy ST-1 test kits (search unblinkingeye for the formula). The selenium toner test is essentially the same thing and is often more convenient since the test solution has a long shelf live and many of us have toner at hand. The method is to put a drop of the test solution on a clear area of film or paper (clear = an unexposed, fixed and washed area). Leave the drop on for three minutes, rinse, blot and check for a stain. Any discoloration other that a slight (very slight) yellowing means inadequate fixation. Refix the prints and adjust your fixer capacities accordingly if this happens. I'll let you search for the particulars.

HT-2 Test for Adequate Washing.
Again, you can buy or find the formula for the HT-2 test. (search unblinkingeye for the formula and the estimator strip.) The test method is similar: a drop of the test solution goes on a clear area of film or paper. Stain is then compared to an estimator strip to tell you just how washed the material is. I prefer to wash till I get no stain.

There's a lot more detail that's not here, but you can find all of that after you decide on which materials and methods you want to use.

Do search. Feel free to do a site search here with the topic and my name if you feel like reading the voluminous posts I've made on the subject in the past. There's lot's there

Best,

Doremus

Doremus Scudder said:

I'll wade in here too.

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Thanks for all the info!

Doremus Scudder said:

First, however: dcy, you really should search here and over on the LF forum for answers to your questions. There is a ton of information on both sites just for the Googling.

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Yeah. I've been a lurker for around a year before I made an account. This forum is a treasure trove of information.

Doremus Scudder said:

Fixing RC paper:
Use the manufacturers' throughput capacity suggestions. You'll be plenty safe here, since the manufacturers build in a generous safety factor. Overfixing RC paper isn't much of an issue either, since, like film, the fixer can't soak into the substrate. There are tests for adequate fixing and washing that I'll address later.

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That's good to know.

Doremus Scudder said:

HT-2 Test for Adequate Washing.
Again, you can buy or find the formula for the HT-2 test. (search unblinkingeye for the formula and the estimator strip.) The test method is similar: a drop of the test solution goes on a clear area of film or paper. Stain is then compared to an estimator strip to tell you just how washed the material is. I prefer to wash till I get no stain.

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Thanks. I found the formula in unblinking eye. I got the smallest/cheapest bottle of silver nitrate I could find and in theory that should make more HT-2 Test than I can use in a lifetime.

Doremus Scudder said:

Do search. Feel free to do a site search here with the topic and my name if you feel like reading the voluminous posts I've made on the subject in the past. There's lot's there

Click to expand...

Thanks.