Ethol LPD Replenishment

logan2z · May 16, 2024

I've been using Ethol LPD as a print developer for a little while and it seems to work very well and live up to its name as a Long Lasting Paper Developer. I would like to use it in a replenishment system but can't seem to locate replenishment instructions that work for the liquid concentrate, which is the form of LPD that I'm using. I contacted the manufacturer and they told me that they no longer publish replenishment instructions but that I should search the internet for them. I've found several sources of replenishment guidelines but most are for the powder form of the developer only. I did find this passage in a PDF online that discussed replenishment:

I have to admit I'm not entirely sure what this means. I use the 1:4 dilution when mixing the working solution of LPD from the liquid concentrate. These instructions say to mix the concentrate using a dilution of 1:2, which becomes your replenisher. It then says to print using 'the normal concentrate working solution' and replenish using the replenisher after approx. 20 prints. When they say 'normal concentrate working solution' do they mean whatever dilution you used to create your working solution, so 1:4 in my case? So I would replenish the 1:4 working strength solution in the development tray using the replenisher made 1:2 from the concentrate? Or should the replenisher simply be made using the same 1:4 dilution as the working strength developer I'm using? Confused

NedL · May 16, 2024

Here's an old thread about it.

I replenish LPD from stock solution rather than a diluted "replenisher". I keep a little tally to keep track of how much paper has gone through it and add about 20ml of stock for every 3 8x10 prints.

As you know, it has a lot of capacity, so you don't need to replenish after every 3 prints, just at that rate! Sometimes I need to pour a little bit off to make room for the replenishment, but you might not find that necessary ( I don't seem to have quite as much carry-over into the stop as some people )

I'm not happy with my last batch of LPD and am getting ready to make some DS-14 and try that. It was in a pouch not a can, and is very brown. It's so brown that it stains my paper a little.

MattKing · May 16, 2024

Here are the instructions I base my calculations from - the powder version in my case:

I'm not sure, but the reference to "Concentrate/LPD" may be a reference to the liquid form.

This happens to be the last page of this, undated booklet that I have a pdf version of. The other 9 pages of that booklet all deal with Ethol film developers.

logan2z · May 17, 2024

MattKing said:
Here are the instructions I base my calculations from - the powder version in my case:
View attachment 370581

I'm not sure, but the reference to "Concentrate/LPD" may be a reference to the liquid form.

This happens to be the last page of this, undated booklet that I have a pdf version of. The other 9 pages of that booklet all deal with Ethol film developers.

Thanks Matt. That's the same PDF from which I extracted the final paragraph on replenishment.

My questions still remain, the replenishment instructions for the liquid (assuming that's what's referred to as the 'concentrate') are still unclear to me given the dilution I'm using. Maybe I'll switch to the powder form of the developer since it's less than half the cost of the liquid and not bother with replenishment at all.

koraks · May 17, 2024

logan2z said:
So I would replenish the 1:4 working strength solution in the development tray using the replenisher made 1:2 from the concentrate?

That's how I read it, yes.
It's also what makes sense, because the replenisher is generally (always) a more active version of the working developer. As such, it wouldn't make sense to have a 1+2 replenisher for a 1+2 working strength developer, since this would mean you start at a certain level of activity and this will consequently drop over time as replenishment progresses.

The exact rate of replenishment seems like a bit of guesswork and I suppose that's inevitable; it'll depend what kind of paper you process - esp. fiber vs. RC, since FB will soak up a little more developer and thus, your replenishment rate will be higher, even if the actual emulsion is the same. In practice, this likely won't matter too much, in particular because paper development goes to completion, so as long as your developer activity + developer time are sufficient, you'll be OK.

Kino · May 17, 2024

NedL said:
I'm not happy with my last batch of LPD and am getting ready to make some DS-14 and try that. It was in a pouch not a can, and is very brown. It's so brown that it stains my paper a little.

That's very discouraging. I hope they don't go the way of the Dodo with poor quality control...

fiddle · May 17, 2024

NedL said:
I'm not happy with my last batch of LPD and am getting ready to make some DS-14 and try that. It was in a pouch not a can, and is very brown. It's so brown that it stains my paper a little.

Ive had the same experience with LPD. Pouch, mix looked like coffee.

Kino · May 17, 2024

My replenished LPD is dark amber, but I've never had it stain the paper.

For what it's worth, I remember mixing 10 gallon batches from cans in the early 2000's for a University Darkroom and it was clear with a distinct, sweet odor. The pouches now mix darker and without the signature sweet odor.

I don't know what has changed, but it has changed...

logan2z · May 17, 2024

koraks said:
As such, it wouldn't make sense to have a 1+2 replenisher for a 1+2 working strength developer, since this would mean you start at a certain level of activity and this will consequently drop over time as replenishment progresses.

That makes sense. However, the instructions on the bottle mention that one possible dilution for the working strength solution is 1:2. So if your 'normal working strength' is 1:2, then having a replenisher mixed 1:2 wouldn't make sense, given what you said above.

I'm still confused

logan2z · May 17, 2024

NedL said:
Here's an old thread about it.

I replenish LPD from stock solution rather than a diluted "replenisher". I keep a little tally to keep track of how much paper has gone through it and add about 20ml of stock for every 3 8x10 prints.

So this is a replenishing scheme of your own invention?

Kino · May 17, 2024

logan2z said:
So this is a replenishing scheme of your own invention?

This is also the system I use. It is outlined in the above posting #3 by Matt.

I use 1/3 oz per 8x10 for replenishment after a session.

Kino · May 17, 2024

Unfortunately, like many things in darkroom procedures, all you can do is try it.

If you do, report back and let us know your experiences.

I could stand to drop my contrast somewhat, but opted for the higher strength in my Nova Slot processor as I was unsure how stable a more dilute developer might be in this unit. So far, it's be very stable...

koraks · May 17, 2024

logan2z said:
So if your 'normal working strength' is 1:2, then having a replenisher mixed 1:2 wouldn't make sense, given what you said above.

Yeah. Then the other remark would kick in that "hey, it's going to completion anyway, we're close enough...."
In case of doubt:
* Do a development test at the start of a session (or halfway) to establish the minimum time to reach dmax
* Replenish a bit more

It's safe to err to the long side with development and the high side with replenishment.
Don't overthink it; just give it a go, see how it pans out.

I use my paper developer (not LPD) replenished as well and basically just wing it. I'm getting away with it, too...

NedL · May 17, 2024

logan2z said:
So this is a replenishing scheme of your own invention?

It's adds fresh chemicals at the same rate as Thomas Bertilsson's instructions in the thread I linked. I've kept bottles going for several years. As Koraks pointed out, since paper is developed nearly to completion, this replenishment would probably work for whatever dilution of LPD you like to work with. But my experience is with 1:2.

Kino said:
My replenished LPD is dark amber...

Yep, dark amber is my experience too, slightly reddish-amber after years of use. This is nothing like that... I can't see the print developing in the tray through 1/2 inch of it. Darker than cola.

logan2z · May 17, 2024

NedL said:
It's adds fresh chemicals at the same rate as Thomas Bertilsson's instructions in the thread I linked. I've kept bottles going for several years. As Koraks pointed out, since paper is developed nearly to completion, this replenishment should work for whatever dilution of LPD you like to work with.

My concern is that this might change the overall dilution of the working solution as its replenished, and hence alter the tone of the prints. I'm currently printing a series of photographs for an exhibition and want to ensure that the tone of the photographs is consistent across the series.

koraks · May 17, 2024

logan2z said:
My concern is that this might change the overall dilution of the working solution as its replenished, and hence alter the tone of the prints.

Try developing to test prints/strips, one in a 1+4 dilution, the other in 1+2. Adjust the times in the baths so that both go to completion. Observe the difference. Then use that to figure out whether a 'dilution drift' due to replenishment would be problematic for your printing.

MattKing · May 17, 2024

Factorial development seems to be in order.
I lucked into a pile of the old cans, due to the generosity of a forum member. The powder and the freshly mixed concentrate is definitely discolored, but it still works well.

NedL · May 17, 2024

The idea is that printing 3 8x10 prints uses up the amount of development chemistry that is in 20ml of stock solution. When you replace the chemistry that was used up, you recover the original dilution. It's not perfect, since low-key prints use more developer than high-key prints, and bromide builds up over time, but it becomes pretty darned steady!

Edit: you would top-off with water if necessary. Just like in Thomas' scheme, you might need to pour out a little to make room for all the replenisher.

MattKing · May 17, 2024

I think that a critical factor in any successful replenishment scheme is that any liquid that is removed - either through carry-over or removal before adding replenisher - includes with it a fair amount of development byproducts, such as bromides.

Kino · May 17, 2024

In the Nova, if I need to replenish 5 ounces due to printing activity, I will drain 10 ounces into a beaker, mix the fresh replenishing developer into the slot tank and then bring it back to the proper level with the used developer. I always have surplus used developer, which is then discarded,

Since I mainly use RC paper and carefully squeegee the backside of the print as I change slots, I probably tend to lose less developer volume than when someone else uses trays and develops fiber paper.

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