Color Paper Top Emulson Layer

[Photo Engineer]

I have actually coated color paper. There is no blue dye layer that is washed away. I assure you! The dye alone is washed away.

PE

[anikin]

Funny, I had exactly the same impression as the OP. I even made up a theory about it. I thought it was a color filtration layer that would be used by the paper manufacturer to do precise filtration adjustment after all light sensitive layers are coated to correct for batch-to-batch variations of the emulsion. On Fuji paper it surely looks like a surface coat. Maybe I should cut a thin slice and look at it under the microscope to prove myself wrong

[RedSun]

That was what I read regarding the Fuji CA paper. I just do not remember the terminology and the source of it. The blue coating does not do much, if I remember it correctly.

Well, whenever you say anything different, there would be many people trying to TEACH you. That is what I've learnt so far at APUG. I just need to learn how to ignore it....

[RPC]

I have a question for our paper experts in this thread.

When one prints a color negative without any filtration in the enlarger the print comes out with a strong orange cast. This is counterintuitive to what what one expect. The paper, reversing the colors, should give a strong blue-green cast to the print due to the orange cast of the negative, but it does not. It is as if the paper is negating the orange of the negative and then some. The enlarger filtration of course, negates the orange in the print to make a color-balanced print.

I have always thought that the dyes that wash out of the paper might have had something to do with this paper color-adjusting act during exposure, but now I am not so sure. Just what is going on?

[kevs]

RedSun,

Yes you're seeing dye that's dissolving out of the emulsion. You'll see a similar thing if you presoak certain films (FP4+ 120 for instance) - it can be a shock the first time you experience it! Trust me, PE knows a lot more about photographic materials than you, me and most of us on here. APUG is a great place to ask and learn stuff, but some of us don't tolerate fools gladly... :-)

If your blacks are coming out blue on your prints per your OP, your developer is getting exhausted (iirc) and needs changing or replenishing. It's nowt to do with dyes not being washed away...

Cheers,
kevs

[RedSun]

No, no, you completely misunderstood what I was originally asking. Same with most of the people, even PE. This is funny.

I was printing test strips, from 18% grey negative, for calibration. The strips are 1" wide, 5" long. I exposed 1/2 of the strip and left the other 1/2 un-exposed in order to get white base for comparison.

I've done this many times and I never had problem with it. But this time, the white un-exposed 1/2 strips came out light blue. The blue color is darker near the thin edges where the strips attached to the Jobo test drums. When I washed the test strips in tap water, I could see that some of the blue color can be rubbed off with hands and running water. So clearly the strips are not washed well.

The un-exposed paper never received light, no safelight, as PE suspected. The blue color is the coating, not actual image dye.

Here I'm doing an experiment. I cut a strip of Fuji Super C paper. This paper has never seen chemical. Then I put the paper under faucet with drops of water. Here you can see clearly that the blue color was washed off (or washed away) by the running water. There is nothing to do with the chemicals.

With all this, it is clearly that I should not have skipped the final rinse stage. The original blue coating was not 100% washed away.

I know this whole thing made a fool of some body, or some people. But common sense prevails. The problem with APUG is that, people always want to teach a fool, not realizing that who the fool is

Sry no flame here. I just do not understand why folks made it too complicated.

Thx for the help anyway.

[frotog]

That was what I read regarding the Fuji CA paper. I just do not remember the terminology and the source of it. The blue coating does not do much, if I remember it correctly.

Well, whenever you say anything different, there would be many people trying to TEACH you. That is what I've learnt so far at APUG. I just need to learn how to ignore it....

Yeah, that's right...ignore it. You're clearly better off not knowing.

[AgX]

Sry no flame here. I just do not understand why folks made it too complicated.

Lurking at this thread from the beginning, it's kind of looking at two worlds apart...



(Can't think of a fine way to bridge them as seemingly I'm founded in that Rochester guys' thinking too.)

[wogster]

No, no, you completely misunderstood what I was originally asking. Same with most of the people, even PE. This is funny.

I was printing test strips, from 18% grey negative, for calibration. The strips are 1" wide, 5" long. I exposed 1/2 of the strip and left the other 1/2 un-exposed in order to get white base for comparison.

I've done this many times and I never had problem with it. But this time, the white un-exposed 1/2 strips came out light blue. The blue color is darker near the thin edges where the strips attached to the Jobo test drums. When I washed the test strips in tap water, I could see that some of the blue color can be rubbed off with hands and running water. So clearly the strips are not washed well.

The un-exposed paper never received light, no safelight, as PE suspected. The blue color is the coating, not actual image dye.

Here I'm doing an experiment. I cut a strip of Fuji Super C paper. This paper has never seen chemical. Then I put the paper under faucet with drops of water. Here you can see clearly that the blue color was washed off (or washed away) by the running water. There is nothing to do with the chemicals.

With all this, it is clearly that I should not have skipped the final rinse stage. The original blue coating was not 100% washed away.

I know this whole thing made a fool of some body, or some people. But common sense prevails. The problem with APUG is that, people always want to teach a fool, not realizing that who the fool is

Sry no flame here. I just do not understand why folks made it too complicated.

Thx for the help anyway.

There is another possible reasoning for this, it's easy to make a powerful but cheap red laser, it's a little harder to make a powerful but cheap green laser, it's harder still to make a powerful but cheap blue laser, for example CD and DVD players use red lasers, a lot of true laser printers also use red lasers for exposure, even when dealing with other colours. Paper intended for machines like the Fuji Frontier might have a blue dye layer, simply to help out the blue lasers in the machines, to get a good exposure.

[RedSun]

This is what I was thinking. The other possibility is the compromise between traditional optical vs digital printing. Blue/cyan coating would make the exposure time longer.

I was thinking my blix chemical is bad. But it is not the case since this coating has nothing to do with developing.

All the Fuji CA papers I use have this blue/cyan color coating.

I'm not sure.