It will contain "a" stain. What the color is is yet to be determined regarding its effect on the rest of the process.
PE
PE
Dye-Imbibition (dye-transfer) & Carbon printing
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OP
OP
Frankly, I spoke to soon, but I think there is some iota of sense behind what I'm saying. I'm just saying, imagine a dichromated gelatin that is crystal clear (impossible, theoretical) and a dichromated gelatin that has a characteristic yellow stain. How will these two differ in their response to exposure?
One snag will be, how deeply does the stain reach into the emulsion. Indeed, having to expose thru the base means that the interior gelatin will have to be quite well sensitized, which might mean quite a bit of absorption will need to take place.
Actually, this is something I hadn't considered. But spirit sensitization is definitely out, and even soaking it might not get the concentration of sensitizer down into the emulsion as far as necessary.
It might require sensitization in the gelatin mixing stage.
One snag will be, how deeply does the stain reach into the emulsion. Indeed, having to expose thru the base means that the interior gelatin will have to be quite well sensitized, which might mean quite a bit of absorption will need to take place.
Actually, this is something I hadn't considered. But spirit sensitization is definitely out, and even soaking it might not get the concentration of sensitizer down into the emulsion as far as necessary.
It might require sensitization in the gelatin mixing stage.
OP
OP
This appears to be a similar, 2-color motion picture scheme...
Polychromide process. Invented by Aron Hamburger. His 1922 patent GB203358 describes the method of dye-toning. The original negatives were made with a beam-splitter camera. An orthochromatic negative sensitised with erythrosine and a panchromatic negative sensitised with pinacryptol were used. Positive prints were made on duplex stock (emulsion on both sides) the print from the orthochromatic negative was toned with magenta and auramine and on the other side the print from the panchromatic negative was dyed with malachite green and helio safranin. The film was then bleached, cleared, washed and dried. Further details can be found in 'Colour Cinematography' by Cornwell-Clyne pages 339-341
from: http://www.brianpritchard.com/Anorak's Corner.htm
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OP
OP
OK, so last night was successful.... but I woke up to failure! Well partially at least.
I finally got some PF melinex and poured a simple gelatin mixture onto them for my dye-imbibition matrix blanks. I got some really nice, even coatings and I thought I was set! Anyways, I woke up this morning and first of all, they were all curled, which is to be somewhat expected. Tips on reducing this would be great.
The main problem was that one of my best coatings peeled off from the melinex in one corner. This is disconcerting and frustrating, as the whole point of this melinex is that it's subbed and should adhere well to gelatin solutions. It seems that only one had this trouble, and the others stuck pretty well.
I know that I used the correct side, having already made that blunder once, and yet I don't know why it didn't stick.
Anyone (PE, hrst, dyetransfer, etc.) who uses PF's melinex... I would greatly appreciate your insight!
I finally got some PF melinex and poured a simple gelatin mixture onto them for my dye-imbibition matrix blanks. I got some really nice, even coatings and I thought I was set! Anyways, I woke up this morning and first of all, they were all curled, which is to be somewhat expected. Tips on reducing this would be great.
The main problem was that one of my best coatings peeled off from the melinex in one corner. This is disconcerting and frustrating, as the whole point of this melinex is that it's subbed and should adhere well to gelatin solutions. It seems that only one had this trouble, and the others stuck pretty well.
I know that I used the correct side, having already made that blunder once, and yet I don't know why it didn't stick.
Anyone (PE, hrst, dyetransfer, etc.) who uses PF's melinex... I would greatly appreciate your insight!
Well, it depends on the thickness of the gelatin layer. I'm used to putting down about 500 mg / ft squared of gelatin using a 10% solution (average sometimes runs about 8%). This gives me absolutely no curl on 7 mil Melinex. I have dozens of 4x5 and larger sheets coated that way and one is shown in the video of making and coating here on APUG.
PE
PE
My carbon tissues curl up like tube, so I pin them to a cardboard to dry. You may be able to uncurl them by increasing the RH. Maybe a thinner layer of gelatin.
Hard to say why it detached in one corner. Greasy fingers? So no KFC while preparing tissues.
OP
OP
Not having my paper in front of me, I believe I went with a 8% solution of gelatin and about 12mL for a 4"x5" sheet. I added ≈1% sorbitol and that's it.
It curled quite badly, just by letting it dry on a mesh drying rack. Maybe I should tack it to a vertical board? And as for the delamination... well that's beyond me. I did wet the surface before pouring and squeegeed it flat; is it possible that water underneath the gelatin would inhibit adherence?
edit: thanks Robert, I think I will try to pin them. I also thought about the greasy issue.. but no KFC for this kid! We'll see... 3 out of 4 were fine.
It curled quite badly, just by letting it dry on a mesh drying rack. Maybe I should tack it to a vertical board? And as for the delamination... well that's beyond me. I did wet the surface before pouring and squeegeed it flat; is it possible that water underneath the gelatin would inhibit adherence?
edit: thanks Robert, I think I will try to pin them. I also thought about the greasy issue.. but no KFC for this kid! We'll see... 3 out of 4 were fine.
Gelatin, 10% coated at 12 ml / ft square
Here is a photo of 1 sheet of Melenex taken from the video. It contains Silver Halide as well. Note the lack of curl. If anything, I suspect that Sorbitol would reduce curl by increasing the amount of moisture in the coating and therefore it would probably reduce shrinking of the gelatin.
And yes, a water prewet will influence adhesion. The subbing is designed for a dry surface to be coated with a wet material!
BTW, for those who have lately criticized my coating methods, I draw your attention to the overall quality of this coating! It would yield 2 sheets of 4x5 film. I now have a 120 coater as well.
PE
Here is a photo of 1 sheet of Melenex taken from the video. It contains Silver Halide as well. Note the lack of curl. If anything, I suspect that Sorbitol would reduce curl by increasing the amount of moisture in the coating and therefore it would probably reduce shrinking of the gelatin.
And yes, a water prewet will influence adhesion. The subbing is designed for a dry surface to be coated with a wet material!
BTW, for those who have lately criticized my coating methods, I draw your attention to the overall quality of this coating! It would yield 2 sheets of 4x5 film. I now have a 120 coater as well.
PE
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Is 1% sorbitol enough? Should I 'kick it up a notch'? It is quite dry here, I'd guess around 40% or less (it was snowing last night), so perhaps that could be the culprit as well.
Also, the gelatin was purty thick. Hmm... all things considered, at least it was my first attempt; problems are to be expected.
BTW Ron, beeaaaauuuutiful coating!
Also, the gelatin was purty thick. Hmm... all things considered, at least it was my first attempt; problems are to be expected.
BTW Ron, beeaaaauuuutiful coating!
I have no answer for you..
PE
PE
OP
OP
Don't worry, I'll consult the Oracle once I get off work (not Warren Buffet)
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How delicate is the subbing layer on Photo Formulary's melinex? Can it be dissolved or washed away?
edit: Called the formulary and asked this question... other than saying it's a stable material when wet, he said it was a question for APUG. "Someone like Ron Mowrey or something".
Haha..
edit: Called the formulary and asked this question... other than saying it's a stable material when wet, he said it was a question for APUG. "Someone like Ron Mowrey or something".
Haha..
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Well, AFAIK, the subbing is quite stable to abrasion. Wetting or washing can damage it though as it is designed for one time only application of a wet layer or a succession of built up layers.
Don't wet it or add a solvent. It adheres and is strong but not that durable.
PE
Don't wet it or add a solvent. It adheres and is strong but not that durable.
PE
OP
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Thank you very much Ron, this is exactly what I needed to know.
Why I've been using water is due to the fact that it makes sticking the sheet to the glass very easy. It's completely flush and gelatin doesn't get around to the underside. Masking tape wasn't working well, and the pouring went swimmingly with the wet and squeegee'd flat sheets.
Why I've been using water is due to the fact that it makes sticking the sheet to the glass very easy. It's completely flush and gelatin doesn't get around to the underside. Masking tape wasn't working well, and the pouring went swimmingly with the wet and squeegee'd flat sheets.
OP
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Round 2: Instead of getting the top and bottom of the sheet wet, I dripped about 2mL of water under the sheets of melinex and that did an exemplary job of sticking to the glass, while keeping the top dry. This allowed for a perfectly flat surface to pour onto. They are drying now, pinned to a board which will hopefully prevent any curling. Tomorrow morning will tell... I also tried 6% gelatin this time which was less viscous and seemed to coat better with a comb.
Going back to my idea of the PD having enough staining power to restrain UV light into the matrices, here is what Luis Nadeau says in History and Practice of Carbon Processes, pg. 118. "It should be mentioned in passing that the dichromate sensitizer, because of its yellow colour, does have a light-restraining effect, but in order to be really effective, the sensitizer would have to be concentrated. This causes other problems..."
Case closed it seems.
Going back to my idea of the PD having enough staining power to restrain UV light into the matrices, here is what Luis Nadeau says in History and Practice of Carbon Processes, pg. 118. "It should be mentioned in passing that the dichromate sensitizer, because of its yellow colour, does have a light-restraining effect, but in order to be really effective, the sensitizer would have to be concentrated. This causes other problems..."
Case closed it seems.
OP
OP
Here's an admittedly stupid question.
Could one make a carbon print with off the shelf Jell-O?
I'm thinking that by using blueberry, fruit punch and lemon, you would have "reasonable" subtractive primaries. It'd be a cool demonstration for kids or something, and at the very least, worth mentioning!
Cyan
http://brands.kraftfoods.com/jello/products/flavor-finder/berry-blue/
Magenta
http://brands.kraftfoods.com/jello/products/flavor-finder/mixed-fruit/
Yellow
http://brands.kraftfoods.com/jello/products/flavor-finder/lemon/
Could one make a carbon print with off the shelf Jell-O?
I'm thinking that by using blueberry, fruit punch and lemon, you would have "reasonable" subtractive primaries. It'd be a cool demonstration for kids or something, and at the very least, worth mentioning!
Cyan
http://brands.kraftfoods.com/jello/products/flavor-finder/berry-blue/
Magenta
http://brands.kraftfoods.com/jello/products/flavor-finder/mixed-fruit/
Yellow
http://brands.kraftfoods.com/jello/products/flavor-finder/lemon/
Or use plain gelatin with food dyes!
PE
PE
OP
OP
Well where's the fun in that!
Without sugar and flavorings, it will last longer.
PE
PE
OP
OP
But will it be nearly as delicious?? So in short, you're saying that it is possible to make a carbon print with Jell-O?
I guess, why wouldn't it be?
I just think it'd be cool to make a print with straight-off the shelf Jell-O. Will I actually bother? Who knows, but I like getting the ideas out there in case some enterprising young fool decides to go for it.
I guess, why wouldn't it be?
I just think it'd be cool to make a print with straight-off the shelf Jell-O. Will I actually bother? Who knows, but I like getting the ideas out there in case some enterprising young fool decides to go for it.
And, of course you are none of the above, right?
PE
PE
Be careful about those young fools who may be tempted to "eat their 'art out"!
I know of people who have printed silver images on tofu...
(Not to mention the Photo Birthday Cakes)
When the line between art and food thins,
eating can get dangerous... Doobie Cool & Dangerous
)
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OP
OP
:confused: But I'm 40, burnt out and a member of MENSA...
.... ok. I can't lie! You're right. I am indeed an enterprising young fool. Though, I'm definitely starting to sprout a couple of grays.
You 'art what you eat!
Mr. Holmes ,
Home is where the woman is in the darkroom
You will gain this knowledge in next 15 years.
Umut
Home is where the woman is in the darkroom
You will gain this knowledge in next 15 years.Umut
OP
OP
DCG Matrices
Tonight I sensitized 8 4x5" matrices in 3.5% potassium dichromate for 3 minutes each.
They're hanging up to dry and I hope to make some exposures tomorrow. This is my first time sensitizing any kind of gelatin thing, so hopefully it goes well. Anywhoo, just wanted to share a photo.
Tonight I sensitized 8 4x5" matrices in 3.5% potassium dichromate for 3 minutes each.
They're hanging up to dry and I hope to make some exposures tomorrow. This is my first time sensitizing any kind of gelatin thing, so hopefully it goes well. Anywhoo, just wanted to share a photo.
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