From RC to FB paper

[jcn]

Hi all,
Probably a silly question, but I'm completely clueless about FB paper and couldn't find an answer to this...
Ignoring all the other specificities around it (longer washing time/Washaid, curl, etc), how does FB paper compare to RC in terms of printing times?
For example: assuming a similar brand and type (e.g. Ilford Multigrade RC Deluxe and Ilford Multigrade FB Classic), if an RC print at f/8, grade 3 is exposed for 16s would I expect it to take longer, lesser, or the same time in FB paper to achieve the same exposure (assuming the same f stop, grade and print size)?
And is there a way to determine this, or a general rule of thumb? Or is it really a variable thing and can only be ascertained by testing?
Many thanks!
J

 

[Sirius Glass]

The exposure time may be different but generally it handles the same. Search for the Photrio thread on drying FB paper flat.

 

[Pieter12]

It can vary from batch to batch. I generally find FB paper to be about 1/4 stop slower than RC.

 

[MattKing]

The ISO speeds of papers can give you a clue:
Ilford Multigrade (V) RC:

Ilford Multigrade Classic FB:

I'll let others describe how to make use of this .

 

[awty]

There is no getting around doing a test print.
Also FB will have a noticeable dry down time, which will very from paper to paper.
Also also they will very on the affects of toning, mostly tone a lot quicker and stronger.
Also also also it will require longer developing and fixing times. Usually around twice as much.

 

[DREW WILEY]

You can only guesstimate the water temperature of a swimming pool by wiggling a toe in it. Sooner of later, ya just gotta dive in and get some experience to really understand. The workflow of fiber-based papers will be slower, and they certainly need to be washed a lot longer at the end. As far a fixing times go, I simply use TF4 or TF5 archival fixer, just enough mixed at at time for a daily session, and never reused later! Yeah, it costs more, but is way faster and more efficient. What is your time worth? Same with papers - the premium FB papers (nearly all VC these days) are getting painfully pricey; but they can make any RC print look rather anemic by comparison.

 

[BHuij]

My FB paper is consistently somewhere between 0 and 1 stops slower than my RC paper. They're not the same brand. But I've never done scientific testing. If you're hoping for a workflow where you do test strips/prints on RC and then a final print on the more expensive/fussy fiber paper, expect to do some calibrations for the speed and/or contrast differences... and then repeat them every time you buy a new box of either one. IMO not really worth it.

 

[MattKing]

I won't disagree with BHuij.
I will say though that if you standardize on one RC paper, and one FB paper, and observe carefully and make good notes, you should relatively soon start seeing some consistency in the type of adjustments you need to make when going from RC.
You may need to include the type of images in those notes - things like high key vs low key, wide range of negative densities vs. low range of negative densities, predominant mid-tones vs. predominant highlights or predominant shadows, etc.
Essentially, building a bank of knowledge about how to print things, and including the paper switch in that bank.
Where I will disagree slightly with BHuij is in reference to speed and/or contrast differences. At least with respect to Ilford papers, it seems to me that there is much more box-to-box and year-to-year consistency than once was the case in the world of darkroom printing papers.

 

[BHuij]

Yep. I make zero claims to have authoritative firsthand information about how consistent the paper is from batch to batch, other than that I have never noticed any obvious changes between boxes as I've purchased them. It wouldn't surprise me if they're extremely consistent. Ilford has been doing this for a long time, and they seem to be fairly good at it It just seems like one more possible confounding variable.

If you do decide to set up an "RC for tests, FB for finals" workflow OP, I'd be very interested to hear how it turns out for you! I'm stingy enough with my test strips that I just use whatever paper I'm going to use for the final print... even making sure to cut test strips from an 11x14 sheet if I'm printing on 11x14, rather than from an 8x10 sheet. Unnecessary? Maybe. But the peace of mind is worth the marginal cost for me.

 

[RalphLambrecht]

The exposure time may be different but generally, it handles the same. Search for the Photrio thread on drying FB paper flat.

That's exactly right!

 

[MattKing]

If you do decide to set up an "RC for tests, FB for finals" workflow OP, I'd be very interested to hear how it turns out for you!

I don't know that I would approach it for this purpose.
Rather, I would use it if you have two general uses for your prints.
For me, I do everything in RC, including exhibition prints. Most of my prints get shared more informally, or get displayed for a while behind glass - RC is great for that. But if I did do special prints that might benefit from FB, I would start that notebook.