Primer for 20x24 fb printing

kingbuzzie · Sep 30, 2015

Is there a primer somewhere for printing a 20x24? I've never gone larger than a 8x10. I'm a darkroom coop member, so all the equipment is there. Things like: do I swish the developer around on top of the print with a tool while in the tray? Is it better to cut up a 20x24 for the test strips(I hate to waste a piece due to the price), or can I get away with using 8x10 or smaller of same type of paper? Do I do multiple test strips at once from different spots? Any advice would be helpful.

Ian Grant · Sep 30, 2015

I've processed with a sponge before now. I usually buy paper in various sizes from the same batches but most paper emulsions of the same make & type are very close.

Do a smaller print first to determine dodging and burning, sometime you need a touch more contrast in a larger print, You'll need to do a test strip at the larger size and compare it to the first print then adjust, maybe do another. Paper's expensive so it doesn't hurt to be cautious and test strips don't need to be large.

Ian

Ron789 · Sep 30, 2015

I've never done 20x24 but I do 16x20 occasionally. And yes, such large format prints do pose some challenges..... first of all: space. I use FB paper an my process takes 6 trays: developer, stop bath, fixer, water rinse, hypo clearing agent, final wash. So you need a lot of space for those 6 trays.
Then, as you say: keeping the developer in motion. I do that by gently moving the tray, thereby creating a wave moving over the print. I have a sink with large separate compartments so I can fill the first compartment with 2 inches of water, let the tray float in that water and then I can freely move the tray to create motion in the developer.
Weight: such a large FB print, once saturated, gets quite heavy and your normal paper pliers may not hold it well, resulting in the paper falling out when transferring from one tray to the next. I handle such a large print with my hands. I always leave a white margin around the print that I cut off once it is dry, so it's no problem that my fingers leave stains on the edge since that will be cut away later.
As for cost: I just did some calculations and found that if you take a sheet of 16x20 and cut in in 4 8x10's, the cost per 8x10 sheet is more or less the same as when purchased separate in 8x10. So I just decided not to buy smaller formats any more in the future, but just buy 16x20. I can cut that to any smaller size I want.
The other way around is much more difficult..... I would not recommend glueing 4 8x10's together to create a 16x20..... ;-)

Oscar Carlsson · Oct 1, 2015

Make sure your enlarger (& lamp) really can handle the new size. If it is too weak you might now get the same results as when printing smaller, especially contrast will suffer (apparently).

I haven't printed that large myself, the lamp issue is what I've heard from other people printing large.

spijker · Oct 1, 2015

I would recommend that you switch to the single tray approach for this size. I use this for the occasional 16x20, never done anything larger. As Ron789 said, big wet FB papers are hard to handle. For 11x14 and smaller I use the regular approach of multiple trays.

Paul Howell · Oct 1, 2015

As already mentioned check to see how your enlarger will print at that size, use a couple of sheets of 8X10 as test, just bring the enlarger head up to the right height for 20X24 then print some 8X10s as test prints to see how long it takes. I use an Omega D3, when making prints that large I use a 150 watt bulb rather then the 75 watt the D3 is rated for. If your print are really need long exposure time there is a greater risk of vibration. The D3 shoots to floor, are you shooting to the floor or the wall? If shooting to the floor and you have enlarger racked all the way to the top more likely hood of vibration.

There is tray called a print canoe, is like a narrow tray wide enough to see saw a print back and forth, last time I used one for 20X24 I had to stand on a ladder. If you cant find one look a similar tray used for wall paper. Others put plastic on the floor and use a small mop, 3 buckets for developer, stop, and fix. I have a 16X20 print drum, I have seen 20X24, I don't know if a 20X24 will fit on a standard motor drive, the 16X20 just fits. For wash I use a plastic kiddy pool with a couple of Kodak tray siphons, I wash on my patio and the water runs down the alley to the storm drain. To reduce wash time you can use a second pool for hypo clearing agent. Drying is simple, just drying screens. I live the desert, I summer prints dry in less than a hour.

Sirius Glass · Oct 1, 2015

1)

Ian Grant said:
...
Do a smaller print first to determine dodging and burning, sometime you need a touch more contrast in a larger print, You'll need to do a test strip at the larger size and compare it to the first print then adjust, maybe do another. Paper's expensive so it doesn't hurt to be cautious and test strips don't need to be large.

2)

Oscar Carlsson said:
Make sure your enlarger (& lamp) really can handle the new size. If it is too weak you might now get the same results as when printing smaller, especially contrast will suffer (apparently).

I haven't printed that large myself, the lamp issue is what I've heard from other people printing large.

3) Practice sliding the paper [or similar paper of the same size] into the tray and turning it over using a dry tray and then to another tray and then the third tray and the fourth tray to start. It is amazing how uncooperative a large sheet of double weight paper can be. When you have that down repeat the practice sliding a similar paper of the same size into the tray and turning it over using a dry tray and then to another tray and then the third tray and the fourth tray with trays of water.

Screwing up putting a large sheet of expensive photographic paper in the developer unevenly can be most disheartening.

kingbuzzie · Oct 1, 2015

Hey thanks everybody for the suggestions. I will try the single tray method. I am worried now that I won't be able to get the print large enough. I didn't exactly think this through as much as I should. At least I can just cut my paper if it doesn't work...

DREW WILEY · Oct 1, 2015

I do it just like any other black and white print, but do have a sink big enough to accommodate 20x24 trays. I use a Rotortrim to slice of narrow test strips from the 20 inch width, then place these in representative areas of the image which I think important in terms of exposure.
I made my own acrylic slot-style archival print washer, though in small quantities you could use the excellent Kodak tray siphon in a preferably oversized tray.

ChuckP · Oct 2, 2015

You might want to develop for 3 min or longer to keep immersion and drain times a smaller percentage of total development time.

kingbuzzie · Oct 2, 2015

I have eyes bigger than my stomach. After talking to the coop president, sounds like we don't have a 20x24 tray. I just joined so I really didn't do my homework on this. I'll just cut the paper down to 16x20 and have a nice stack of 8x10.

mr.datsun · Sep 5, 2016

spijker said:
I would recommend that you switch to the single tray approach for this size. I use this for the occasional 16x20, never done anything larger. As Ron789 said, big wet FB papers are hard to handle. For 11x14 and smaller I use the regular approach of multiple trays.

This sounds fantastic. I've been wanting to go up to 16 x 20 or 20 x 24 and don't have the room for the trays, so this could work. Has anyone got suggestion for easy-to-pour-into bottles?

ChuckP · Sep 6, 2016

Maybe you could use buckets to empty the trays into and then pour into bottles. Less chance of a spill.

Nige · Sep 6, 2016

I use buckets whilst processing. Once finished I pour the chems into bottles using a funnel as handling the big trays can be difficult.

David Allen · Sep 6, 2016

spijker said:
I would recommend that you switch to the single tray approach for this size. I use this for the occasional 16x20, never done anything larger. As Ron789 said, big wet FB papers are hard to handle. For 11x14 and smaller I use the regular approach of multiple trays.

The single tray method is not just great for large prints but can also be a good solution for smaller prints where space is at a premium.

My only variance with that described is that I use a pre-soak (especially useful with older curly papers) and that I find I need much less chemical volume than described.

At today's prices for paper, I would recommend the single tray approach for prints larger than 16" x 20" (30cm x 40cm).

Bests,

David.
www.dsallen.de

M Carter · Sep 6, 2016

I've done lots of 16x20, and lith printing, so tray warmers, hot water tray for highlights, etc - it takes some practice.

Make sure your tray is big enough to be able to grab the print and pull it out - I have 11x14 trays that are exactly 11x14 it seems - almost impossible to get the paper out without using something to lift a corner (so those get used for 8x10). If you're trimming your prints or doing something more square where you'll end up cutting an inch of paper off, fold that corner up to make grabbing easier.

I have a deep 20x24 tray which is handy for wash and holding. For clearing agent, by the time I'm doing final wash, I've drained earlier process trays. You can hold prints in the bath tub if you need to. You can even stuff some vinyl hose in the tub faucet and run it round to the far side for washing prints if you need more space (heat one end with a blowdryer til soft and just stuff it in the faucet, it will usually hold the shape and stick, at least enough for a decent trickle of water).

Our freaky-old-lady cat is obsessed with drinking from sinks and puddles - I buy litter in the huge plastic jugs and have a nice stash of those, they're like 3 gallons or so, handy for big printing days.

mr.datsun · Sep 8, 2016

Thanks for you suggestions. I'm looking forward to moving up to 20x24. I guess two trays – one for processing and one with water in for putting the prints in while they all wait for the wash... I'm assuming I wont make more than two or three prints at a time and I can store them in the water for a while before washing them at all at once.

DREW WILEY · Sep 9, 2016

Really no difference than making smaller fiber based prints. You just need bigger trays, a bigger sink, and more money for bigger paper. One or two
test strips usually does it for me. I only develop one print at a time. It's easy to tear big prints if you try the shuffle method.

Kilgallb · Sep 9, 2016

I start at 11x14 then when I like what I see move up. It is a simple calculation to increase the exposure times. That said, I usually tile a few 8x10 sheets just to make sure. Then of course I usually realize the Dmax or grey scale for a large print needs to be slightly different from a small print. Then the fun starts. Sometimes I waste a
lot of paper.

Primer for 20x24 fb printing

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