For starters, my ortho-lith use has been trying to dial it in without mixing some special low-con developer. I use HC110, 1:100.
So, in that scenario, the pros for me have been:
Develop by inspection, bright safelights don't fog the film, development is a couple minutes. The stuff is dirt-cheap. It does a fabulous job of making unsharp masks and other low-density masks, holds details very well.
Very easy to bleach with wet (ferri) or dry (iodine), so cleaning up details or bringing density down and so on is easy.
But the cons.
You can't get much density at all. Reach a certain point and everything just blobs up and turns to an abstract cloudy storm scene. So for something like an SCIM mask, or a mask to repair or isolate something - nope.
Selenium intensification or bleach and redevelop - no luck for me in those departments, so getting more density chemically is out.
Looking at the blobby/cloudy response to more exposure made me think "what if I use the developer the film is designed for?" Using lith dev 1+1+3 will give you litho negs, 100% contrast, that's what the stuff is designed for - masking in graphic arts applications.
But what about dilute lith dev, as we use for lith printing, say?
I've found using Arista lith dev at 15+15+240 is… well, freaking fantastic. You get blacks as deep as you need. You get decent tonal gradation (depends on your contact source - I made a sharp but thin positive with HC110, and set out to make a shadow mask).
And: I haven't tested this extensively, but it's potentially huge - litho film in weak developer seems to act like lith printing with paper. You can control contrast by a combination of exposure and developing time and develop by inspection - dev. time at the dilution mentioned has been about 4-6 minutes for me, with an initial couple minutes of no visible activity, so you can nudge the tray and do other things vs. staring for that long. However, development isn't "infectious", it's linear. Development does accelerate, which leads me to…
You can slow down development with a tray of water, 2-bath style… developer left in the emulsion seems to bring up the less dense areas. This potentially opens up 2-bath with even weaker dev. or warm water or other strategies. You can "dodge and burn" by dipping in water, and then dipping partial sections back in the dev, watching the development work.
If you contact your film where a small portion of the lith film is uncovered by glass or film, you get a visual max - black reference, which is priceless under safe lights, and also gives you an idea of when to start watching closely.
Anyone doing darkroom masking - I hope this opens up some avenues and I'd love to hear more results and testing.
A couple tips:
I'm using an office paper punch and silkscreen pins for registration. The film just won't punch that well… unless you stick some regular old office paper under it in the punch. I cut a stack and leave them by the punch, just like a strip that can reach the back of the punch and stick out an inch or so.
Hardening fixer's a good idea, since the emulsion is delicate, and post-processes don't seem that viable.
You can fix by inspection as well, since you can watch the base clear in the tray. I just double that time roughly.
Photoflo and tiny little "A" clamps… give the film a good flick of the wrist after final rinse, clip a corner, and set it on its side on a paper towel to dry (so the clip holds it upright).
So, in that scenario, the pros for me have been:
Develop by inspection, bright safelights don't fog the film, development is a couple minutes. The stuff is dirt-cheap. It does a fabulous job of making unsharp masks and other low-density masks, holds details very well.
Very easy to bleach with wet (ferri) or dry (iodine), so cleaning up details or bringing density down and so on is easy.
But the cons.
You can't get much density at all. Reach a certain point and everything just blobs up and turns to an abstract cloudy storm scene. So for something like an SCIM mask, or a mask to repair or isolate something - nope.
Selenium intensification or bleach and redevelop - no luck for me in those departments, so getting more density chemically is out.
Looking at the blobby/cloudy response to more exposure made me think "what if I use the developer the film is designed for?" Using lith dev 1+1+3 will give you litho negs, 100% contrast, that's what the stuff is designed for - masking in graphic arts applications.
But what about dilute lith dev, as we use for lith printing, say?
I've found using Arista lith dev at 15+15+240 is… well, freaking fantastic. You get blacks as deep as you need. You get decent tonal gradation (depends on your contact source - I made a sharp but thin positive with HC110, and set out to make a shadow mask).
And: I haven't tested this extensively, but it's potentially huge - litho film in weak developer seems to act like lith printing with paper. You can control contrast by a combination of exposure and developing time and develop by inspection - dev. time at the dilution mentioned has been about 4-6 minutes for me, with an initial couple minutes of no visible activity, so you can nudge the tray and do other things vs. staring for that long. However, development isn't "infectious", it's linear. Development does accelerate, which leads me to…
You can slow down development with a tray of water, 2-bath style… developer left in the emulsion seems to bring up the less dense areas. This potentially opens up 2-bath with even weaker dev. or warm water or other strategies. You can "dodge and burn" by dipping in water, and then dipping partial sections back in the dev, watching the development work.
If you contact your film where a small portion of the lith film is uncovered by glass or film, you get a visual max - black reference, which is priceless under safe lights, and also gives you an idea of when to start watching closely.
Anyone doing darkroom masking - I hope this opens up some avenues and I'd love to hear more results and testing.
A couple tips:
I'm using an office paper punch and silkscreen pins for registration. The film just won't punch that well… unless you stick some regular old office paper under it in the punch. I cut a stack and leave them by the punch, just like a strip that can reach the back of the punch and stick out an inch or so.
Hardening fixer's a good idea, since the emulsion is delicate, and post-processes don't seem that viable.
You can fix by inspection as well, since you can watch the base clear in the tray. I just double that time roughly.
Photoflo and tiny little "A" clamps… give the film a good flick of the wrist after final rinse, clip a corner, and set it on its side on a paper towel to dry (so the clip holds it upright).